HOW/WHY DO YOU DO _______??????

Here are the list of glitches used in DKC any%

Fanfare Skip: In versions 1.0 and 1.1 of DKC (US only; the Wii VC version was 1.2) you can press buttons to skip the victory dance that the Kongs do about halfway through. This saves more time in other categories, but it is still relevant here. Not sure if it was intended, but I have no idea why they removed it in 1.2, anyway.

Mapwarp: When you reach a corner in-between stages on the map (only seen in World 1), you stop for 1 frame (1/60th of a second in DKC). If you only have 1 Kong, or you are in Funky's plane, you can press a button (A, B, X, Y or Start) on this frame to warp to a different stage. This "works" presumably because the game thinks that you are trying to enter a stage because you aren't moving and pressing a button at the same time. This is the most popularly known glitch that a lot of people found out just by impatiently mashing B to get to the next stage.

Split-up glitch: By exiting a stage after you have tossed a DK barrel--but before it hits the ground--you confuse the game a bit. It expects you to have your second Kong (Diddy, in this case), but you don't. As a result, if you get hit immediately after doing this, the game hangs waiting for him. However, if you get hit over a pit, it overrides that and kicks you out of the stage. What happens at this point is that the game assumes you should be controlling Diddy, and as such, when you get the next DK barrel, you will end up controlling both Kongs at the same time.

Holding air: This is a fun one. If you ride a steel keg, then pick it up and walk it into a halfway barrel, you end up holding a glitched sprite that, explained simply, is treated as the next sprite that is loaded onto the screen at any time. In the run, I use this to "hold" the bonus opening so that I can enter it without actually having a barrel.

Holding barrels with animals: This is actually unrelated to the wrong warp. Simply ride a steel keg and hop onto an animal. Hold Y as you ride and press A as you intersect with them. Expresso is only needed in this run because Donkey cannot reach the bonus by himself while holding the glitch sprite.

Ghost Kong: you only see this for a few frames in the video, but this is what happens after you do the above glitch and throw the barrel. Donkey is seen riding a darker version of himself. Useless by itself, but amusing.

The wrong warp itself:

Everything done before the warp is to set up changes to the value that determines where the bonus sends me when I exit. The first change is the glitch sprite. I do a quick left-right to make the bonus opening appear when I throw the sprite. It has to be done in a certain spot before I actually reach the wall, or else I'll end up somewhere else. More specifically, the x-value of the sprite when I throw it determines where I end up. Too soon and I'll walk right back into the bonus. Too late and I'll end up in 1-1. I believe there are a few other locations you can warp to, but those are the only ones I accidentally reach.

Next is the end of the split-up glitch. This bonus is chosen because there are only two bonuses with DK barrels in them, and this is the only one that achieves the desired warp. The barrel must be thrown in such a way that both Kongs exit at the same time. This changes the value to what is needed for the warp. If only DK goes through, I end up in 1-1. If only Diddy goes through, the game crashes. Shown in the video is the fastest way (non-TAS) to get them both into the door at the same time.

As the game still thinks we are only controlling Diddy, he ends up being the only one in 6-2. Donkey is presumably lost to the Deep Darkness. Expresso follows us (this only works in stages where there is normally an animal buddy already; Rambi, in this case), which is convenient, as he makes the stage a lot faster and a bit easier as well. After 6-2, the rest of the game proceeds as normal. There are no lingering effects from the glitch.

Dankspin (jumproll):

This is a glitch that can be done pretty much anywhere you can walk off an edge and hit an enemy, but it is only faster than typical movement in a few places. It is done twice in the run; in Misty Mine, it saves about 80 frames. In Platform Perils, it saves a whopping 14-15 seconds, as otherwise you have to jump between all those slow-moving platforms. The glitch is performed by tapping Y (roll) on the same frame that you land on an enemy. As you can't roll during a jump, this can typically only be done when there is an enemy near the ledge that you can bounce on by running forward.

During the glitch, you pass through all enemies except for Zingers (I have no idea why). If there are two flashes when you start the spin, you can roll out of it. Otherwise, you can only jump. That's why I jump out of it in Misty Mine, even though rolling from the dumb drum would obviously be faster.

The Dankspin is a very difficult trick to do consistently, due to the 1/60th of a second window to press Y. Because it saves so much time, though, most high-level DKC runs are over if you miss. You can keep going, but since runs with the trick have already been pulled off, you won't have a record time. In any%, the game is only 8 minutes, so this isn't a big deal. However, in All Stages and other categories, you can lose a good run nearly half-an-hour in.

That one Klap Trap in Loopy Lights:

In the 1.0 or 1.1 version of the game, this guy can be rolled through. He's the only Klap Trap in the game that doesn't walk, so I guess they messed up the coding a bit. If you run or jump into him, he'll hit you, but unlike his brethren, he's vulnerable to rolling primates.

Hopefully that answered all of your questions! If you have any questions about the route, the answer is either "that's the only way it works" or "because it's faster." The only exception is getting stuck at that one point in Manic Mincers. That was obviously a mistake.