I'm not really sure if I should believe this or not. I'm not sure if TSA has actually tried a lot of the glitches on N64 so he might just be doing it wrong. Maybe we can get him to come here and give us some more details.
The only big glitch I concede I have not had much experience with using often is Superslide off a bomb/enemy without Nayru's Love. When I tested it in OoT 3D, Link would basically react like he got hit by 2 blasts; knocked back by the initial blast, and then knocked back the same distance once again. However, here's the problem: When the GRAB icon appears now, no matter what state you are in (Z target + Shield with sword drawn, especially), Link will pick up the item and not get stuck. If he can't pick it up, he does the struggling animation, and then returns to the default animation. That's why many of the tricks using that are now nerfed.
Door of Time - I know you said you saw a GAP, but I clipped the camera through the wall to the left of the DoT with a good angle, and the physical door extends BEYOND the "gap" you say you see. The purposely extended the door into the Out of Bounds zone to cover the gap everyone was clipping through. Plus, many of the walls that you could get through via acute angles are fixed up now, like one of the old ways to skip Boss Key in Forest Temple (via that jump slash in the corner).
Early Shadow - Though the game still loads stuff so theoretically its possible to access areas where something isn't quite loaded yet, in this case, the ENTRANCE to the temple is completely gone in the non-loaded state. I had the camera clip the wall along the stairs down to the entrance area, and when that area isn't full loaded, it's just a void now, no missing door and entrance at all.
ISG - I spent an hour trying this on different things. Seriously, I can pull this off 99/100 times on N64 and it's one of the easiest glitches that anyone can do. Unless there's a new method to activating it, the old way is nerfed.
Megaflip - Tried it outside of Link's house. He cleared the gap and landed behind Saria's house, just like in the video you guys had on the tricks page. Standard backflip fell down into the area where Saria says hello to you.
Cucco Jump - Could still work, I concede I didn't give it much attention because...
Early Desert - Nerfed. They put up a high wall around the top of the platform at the gate. You can't clip through it nor side hop/backflip over it.
Deku Sticks - Seriously, I know how they work. Gohma - Three jump attacks with Deku Sticks should = death. Nope. It's 6 Jump Attacks with Sword, 12 Jump Attacks with Deku Sticks to slay Gohma now.
This is all off a review build. Final retail should be in this coming week, so I'll re-verify everything again (who knows, they might have nerfed what little still worked). We got our capture device, so I will try to get a video up showing some of the proof. However, I know you guys will want to try it out for yourselves before buying all of this, but I still wanted to share this stuff, especially after seeing that one vid that apparently had ISG activated.