I agree with the shutting off jump to give better percision control.
Basically, it would also allow easier diagonial attacks, or even allow those attacks to exist.
I love all the items in the game...but certain items I wish I could turn off (I am lazy to go through and actually turn them off.)
Here is a great idea for next game.
Allow themed Item sets.
This would allow you to quickly set type of weapons you want from a pre-set which would be quicker than editting the list yourself...and then you can also save your own personal pre-set weapons.
Ideas could be:
Melee Weapons,
Mariosintric
Zeldasintric, ect...
All Food (Health),
Lasers & Guns
Bombs & Traps
and so on.