The Librarian
Banned
I don't know Dax, a lot of those control issues like the variance in jump height and careful movement sound more like you're just not that used to the genre at all, if the undemanding RPG/platforming hybrid that is SPM was indeed your last game that even approached being a 2D platformer then you might have been better served by trying a NSMB game first before jumping into DKCR.
Still you enjoyed it and finished it so there's certainly that. Bosses are one of the few things in the game that i'd consider being pretty weak, Mangoruby being the only one actually enjoyed.
It's a great game. I'm kinda mad at myself for not getting it early, but now only have to wait two months for Tropical Freeze instead of three years! I'm replaying the game (up to World 2 right now) and I find myself enjoying the levels more than the first time through. I think it's because I know what to expect, whereas playing it the first time through I had no clue, so I'm adjusting my play-style accordingly. Haven't encountered the problems mentioned in the OP up to this point, and I remember on my first try I was having some difficulty...