First Message from JKT on how to make a TAS in MV:
Ya i've read it long ago, but just haven't got to it.. and about  Q1 Flap that's kinda a lost cause now, they're all gone along with some of my X's TAS in some old HDD that i can't find anymore. But nothing to worry about those TAS's aren't exactly 100% optimized or perfect in anyway it was pretty good but still lots of room for improvement. It's still possible to redo them and improve them further, it all comes down to how you're angled while drifting. While its important to cut the track as sharp as possible there are few times on Q1 where i didn't cut sharp at all but my drifting angle is so deep its almost JDT angle and that somehow ended up being "05 faster than a sharp cut so taking that into note. All i know is even though i got 15"00 on Q1 i am sure it could still go lower slightly 14"9x or so maybe even 14"8x but i haven't even tried doing frame by frame perfection i was just playing the game at slow speeds with savestates and re-recording. And yea i've looked at K2 and B3 and those really do look like it could be crazy with TAS.
As for the Visualboyadvance advice thing on the basics. There's really not much i can think of that would be a big mistake for beginners, maybe accidentally overwritting your TAS VBM file and losing most of everything you worked on so far. That can only happen like this, example say you already finished a TAS VBM file its 1 min long has whatever number 2000 rerecords and 1500 key inputs on some track. You play the file back, and lets say it didn't finished playing through the whole 1 min in length, you played up to 20 seconds and accidentally hit the savestate key for example. then the rest of the 40 seconds on that file will be gone.
Basically all the emulators that support re-recording made for TASing all use the same concept. That would be example:
1. Have the emulator that your using and the game rom, which you have i think but not sure if its the one made for TASing that would be VBA-rr emulator.
2. Load the game pick the track course or anything that you want to make a TAS for.
3. There's a movie recording option on every emulator that supports re-recording and thats where you begin. For VBA-rr its under Tools -> Movie -> Record New Movie
4. Configure the emulator to how you want it, know your keys;  Savestate (normally Shift+ F1 through F10), Loadstate (F1 through F10), Frame Advance(Ctrl+N) and game Speed for slowdown (- or + key)
5. After you start a Record New Movie to create the TAS always do a Savestate and Loadstate on the first frame so that from there on if you mess up something you can always Loadstate back from the current frame.
6. If you already TAS'd several seconds into the run but couldn't Loadstate at an earlier part in the file then just go to Tools -> Movie -> Play Movie and replay the file up to where you want to begin and Savestate Loadstate again.
7. thats basically all for starting out. if later in the future you have several TAS's completed and wanted to combine them you can always use TASedit to stick them together http://www.bluetoaster.net/emu/tools.htm though you might not need to atm.
I do the same when TASing X also open up emu and rom pick track start record movie file do a savestate loadstate then play through the course at slow speed when i screw up somewhere and need to make adjustments I just open and play back the movie file for n64 its .m64 for vba its .vbm, and when i am done and want to export to an avi file so i can upload somewhere, i just select play movie file then start avi recording, its in the options in there for all the ReRecording emulators and thats it.
Oh and yea don't forget to stop movie recording and avi recording if your done.
Anyway goodluck with trying out TASing MV.
Second Message from JKT on how to make a TAS in MV:
I play with both keyboard and the gamepad but mostly gamepad and slowed down to around 25-35%. And yea you can't set the frame advance and savestate and pause on the gamepad so all of that has to be on keyboard. Takes a while to get used to it, but its not too much a problem.. i just have my hand near the keyboard while holding the controller so when i need to loadstate/pause/frame advance fast i hit it with my with the fingers which are just holdin the controller. I also only frame advance parts that i have trouble doing smoothly on the controller, and although frame advancing the entire thing would make your run absolutely perfect, although it also takes forever.
It's better for the people who have total knowledge about the game inside out to attempt to frame advance everything since you take less time figuring out whats ideal to do and whats not. Example as you see when someone like comicalflop first tried his attempt at TASing FZX he started on MC1 with just the first part the beginning bounce railslide, frame advancing everything, so basically he has to try every angle value input to get the ideal best slide and that takes forever although he did sorta of got it, but it took so much time that he gave up and Lordtom had to pick up where he left off. Doing everything in frame advance means you have to find the best key inputs to produce the best results, could say for example on MC1 in FZX the ideal starting out angle to enter a railslide at the beginning of a race is 30 degrees which means the rest of the degrees from 1-29 and 31-99 would not beat the speed angle 30 enters at, it will change depending on the turn of each track could be angle 35, 40, 25, who knows but thats one example. Even though Lordtom and Comicalflop both do really good frame advance TAS's in other games they just don't have the full indepth game knowledge like us in our FZ games so even though when they finish a run, someone like me or daniel could just add few small adjustments to the TAS, and still end up beating or improving the TAS in their work cause they didn't know about that small adjustment stuff. So to be able to have the most ideal TAS it's better for someone to know both TASing well and the game itself. Even though i may know alot about MV, there are times i still have to experiment alot with to find the best results, but you probably already know those better than me or at least it would take you less time to find something ideal. I could try to TAS any course in MV but since i haven't played MV overall as much as you i probably may have overlooked something, so to say it might not be completely optimized it may seem fast but maybe there is still a different approach that you would probably have done which is even faster. For those who TAS without knowing anything about the game would have to try each and everything per frame and that takes forever probably would never finish.
So just saying frame advancing is nice but since it has the ability to make the run godlike it takes too long to figure out the best input for everyframe. Its much easier to frame advance games with less buttons or keys, anything with analog in it is obviously not going to be easy. So far almost none of the 3D racing games i've seen are TAS'd down to 100% frame perfection. It has to be a simple input game like mario for nes up down left right A B those are all you have, so not much to test its more easy to find the absolute best input with just that. Although MV is not analog, its just Up Down Left Right A B and shoulder buttons L R, while the game has drift angles that might still take a bit too; like say holding R+Left 1 frame drifts the car a degree or two hold that same R+Left for 2 frames and now the car drifts 2-3 more degrees and holding it for 3 frames and so on, gives so and so drifting degree angle trying to find out the ideal for that in each turn is going to take a while too.
My Synobazz Championship TAS is by no means frame perfect its just played normally slowed down 25%. I don't even want to think about how long it would take me to input every single possibility just on the opener itself to find out what is the absolute max you could get. 17"45 is the opener i ended up with but i think it could still be way way better i just haven't tried everything yet thats just how i choose to play it, maybe a different DDT setup or drift pattern at certain frames could improve it by way more but who knows.
Frame advancing is not easy stuff when you do it, it means you absolutely know that at each frame xxx and xxx no other key inputs would produce better results and that is the final key input anyone who TAS will arrive at. Could say 10 different people TASing same game but all of them end up using the same input for the game at xxx and xxx frame then you know those are frame perfect inputs cause nothing else tops it, unless unknown person 11 finds out a special glitch at a certain frame and skips something which saves time then those previous 10 people didn't frame perfect it cause they all missed the glitch. Another easy example would be trying to find the exact ideal frame when to hold accel to get a boost start, of course everyone who TAS's will no doubt end up at the same frame cause everyone would all know there can only be 1 perfect frame to hold accel at to get the boost start, while the rest of the frames either get no boost start or is unneeded frames for holding accel. Same can be said with taking corners etc. Would be nice to see a frame perfect F-Zero TAS, i think FZSNES is the closest to frame perfect for the normal run without pause glitch, but if it can still be improved then it means its not perfect yet.
You can try frame advancing, but for now i think playing slowed down is easier, even a 5 second TAS can take weeks to do, and a full 1 min+ run would probably take months or even year+ to frame perfect. 
I'm still working on Devil's Forest 4 - DD track FZX TAS i have already made a first strat test which already beats the current WR by 5-10ish sec, now i am going to test my 2nd strat and try to beat that one by another 5 or so sec. It looks really sloppy atm heh anyway thats all.