I like this site name cause it's easy to remember.
What glitches are you thinking of? And what race, specifically? It really depends - for example, the one that can get you 00"0 time isn't allowed, because a record wouldn't measure skill.
I would think the backwards longjumping on the elevator would be acceptable, because you don't go through anything in this case, but it would be unimaginably difficult to save any time. I mean, really, really hard. You could, theoretically, do it very very fast though.
I like this site name cause it's easy to remember.
If you can pull it off, it would probably be allowed, but I think it would have to be a new category, just like the w/shell and stuff.
About the 00"0: 1. Turn on cannons. 2. Get Wing Cap. 3. Swoop down to the Koopa and start the race, but don't touch the ground. 4. Fly into a cannon without touching the ground. 5. Through repeated cannon use or whatever, get to the flag without touching the ground. 6. Wait for Koopa. If you never touched the ground, your time should be 0'00"0. Of course, this glitch or anything resembling it is not allowed.
Na not 12, without glitches and Koopa still giving you the star, it's around 18 1/2 seconds.
On a related note, the multi-way tied record of 12.4 on the Princess Slide was recently lowered to 12.3 by Curtis. Myles and I re-tied it within a few days of his accouncement. FODA was the first to hit 12.3, but on emulator.
Curtis, Myles and I made videos for it (posted in MK MB). Curtis's had a good bounce at the bottom of the slide, but he was 0'1 slower than me at the top, so 12'2 is definitely possible. The challenge lies in timing the ricochet at the bottom, so I'm not sure why he was slower at the top (it's the "easy part", hehe).