The biggest improvement that can be made to my 100% run is dying in 2 levels that have early warps in them after I get the bonuses.
Wall jumps are possible but I have only done them in world 2. I don't know if it has anything to do with the walls but I never really understood them.
I have gotten a double jump off tires (I think I mashed A and I got it) and I think I have gotten it off of enemies.
I know you can jump in midair after some barrels shoot you. I don't really know what triggers this but I believe all midair jumps are timer based. I'm certain I'm wrong at this but I sometimes delay when I do things to avoid double jumps.
I found this a few days ago
http://www.twitch.tv/wawlconut/c/1922258
I think I hit B and A on the same frame I hit the Krusha but I really have no idea how it happened.
Ropes have weird physics. I'm not sure if I entirely understand them but I feel like they retain my speed so it's always important to approach a rope while going fast. Having this fast speed allows a pixel perfect (I believe it is pixel perfect) skip in the boat levels. If a video needs to be provided to explain in further detail what I mean I can easily do so since this is hard for me to describe.