I have searched each guide and probably half the threads on the Marth thread.
I still have some questions...
---What is the best way to ensure short-hopping?
---How do you do an Aerial attack off of an edge?
---Is DIing solely control-stick or a combo of the c-stick and control stick?
---Is it ever "just" to use the 3rd Down B Combo for a spike?
---Is the Y button a taboo button to use to jump?
These questions are all answered in threads throughout the boards, but...
1. To short hop, press the X or Y button as quickly as possible. Treat it like a 300 degree hot burner.
2. If you're hanging on the ledge, simply tap down to fast fall or to the side then jump while at the same time performing a backward air attack. Be prepared to use your up B afterward to make it back to the edge. This takes practice.
3. I DI with just the control stick and do just fine. For example, if you're hit horizontally to the right off the stage, you want to tilt the control stick in the upper-left position for maximum DI. There is also a thing called Smash DI, but that is waaaaay beyond your level to master.
4. You do not want to use the dancing blade 3rd down B combo off the stage. There are much safer, more accurate ways to edge guard. The dancing blade is best used if your opponent is really close to you and you need some space. It's a way of saying "back off, buddy!"
5. Y button is JUST FINE FOR JUMPING!!! Many pros use the Y button instead of the X button, or the Y button and the X button. Whatever you're used to using is the best choice. I personally use just the X button.
Hope this helped.