[quote name='crunchewy']Pretty much all of it, though I can do the single quarter circle one fairly reliably. I struggle even with that power uppercut attack (I can't remember the names) where you make a Z shape, though certainly I have more luck with that then the super and ultra combos. The main one is the super and ultra that have you do that quarter circle twice. Can you pause a long time in-between them or do you have to be fast? That was real unclear and so I kept trying to do it very fast. Plus I inevitably end up jumping by accident.[/QUOTE]
Don't worry, man. You're not alone. Everyone struggles with the double quarter circle motions (QCF) the first time they see them. You just have to build the muscle memory for it.
I know it sounds really obvious, but you're pressing the stick too wildly if you're jumping while trying to do it. Take a second to actually look at your hands while you're doing the motion. A lot of times, you won't realize how erratic your motion is unless you see it. Also make sure to turn on Input Display in Training Mode, so you can actually see what directions you're pressing.
SSFIV has input shortcuts. While you should work on execution so you go neutral between the QCFs, you can "cheat" by running the the stick in an arc from down to forward, then rolling to down, then rolling to forward again. You want to make sure you press all three punch buttons when the stick is in the Forward direction though, otherwise the input shortcuts will read an EX-Shoryuken.
As for the Shoryuken motion, the easiest way to think about it is doing a QCF immediately after walking forward. You walk forward ->, then roll from Down to DownForward, and hit the punch button. That will at least allow you to get the motion consistently so you can work on doing it without exaggerated motions.