how does buffering work? I hear about players buffering rolls, how does one do this? Can you buffer a nair out of shield so it comes out the first frame possible?
for ice climbers side-b and doc/mario's down-b, is height determined by the speed you press b or do you also need to hold up on the analog stick?
when a character misses a tech and is on the ground, when are they invincible? what attacks can hit a character when they're on the ground?
when a fox is waveshining you across the stage, can you di out of it? what about SDI-ing the shine that sends you off the stage to avoid a shine-spike?
if you're on the ledge at high-percent, do any of your options provide invincibility (get-up attacks or roll)?
1.a Buffering does not really exist in melee as it does in Brawl. The closest thing is IASA frames, or "Interruptable As Soon As" Frames. Instead of waiting for the current attack to finish (say Marth's forward aerial) and stringing another forward aerial after it with no frame delay in between, which is what buffering is, an attack with the IASA property (check out your character's frame data stickies to look at these) can actually be interrupted during its animation. So, if you're Marth, and you've just used forward air, at a certain point in the animation (frame specifics are again, in the stickies) you can input the command for another attack, including another forward air, and that will end the attack animation prematurely (the hitbox still came out, though, dw about that) and start the next attack. That attack can be interrupted as well.
1.b When players talk about buffering rolls, they are not "truly" buffering. Buffering is defined as inputting the command for an action before your current action has ended, and the game picking up on that input and, once your current action is complete, starting the next action (which you inputted) for you, immediately afterward. Melee will not do that automatically for you, you must input manually. The exception comes when you have to use one of the analog sticks for the action. If you smash the gray analog stick up, Melee reads it as an input for a jump. If you keep it smashed up, and you don't let it snap back to center, Melee will not continually read "jump" inputs, just as it will not continually read "laser" inputs if you were playing Fox and just holding down the B button. However, if you go into any sort of attack stun (shield stun, hit by an attack), the very frame you come out of the stun, Melee will re-read that analog stick you've been holding up. It will accept it as an input for a jump.
While shielding, when an opponent is attacking your shield, and keeping you in shield stun, you can hold the c-stick to either side, and as soon as the player's attack rhythms come to a point where they are not shield-stunning you frequently enough, a gap opens where you're no longer in shieldstun, and the game has read the input from the c-stick you've been holding to the side. You have rolled at the earliest possible time. You have "buffered" a roll.
1.c This explanation applies to jumps as well, when you hold either analog stick upwards out of a shield. But notice that to nair, you have to press the A button. Melee will not buffer button presses. You can buffer the jump that puts you in the air for the N-air, but you will have to time the N-air yourself. It's a manual input only. Takes practice to get it frame-perfect.
2 It is purely the speed at which you press B. This is something you could have tested yourself.
3.a Characters are never invincible for any reason when they hit the ground. If you hit the ground you're just as vulnerable as you were if you were standing up. The game allows you invincibility frames only after you've pressed the L, <-L->, or A/B buttons, so you have time to get back up. Search through frame data stickies to find out more specific information about invincibility lengths.
3.b Any attack that has a low enough hitbox (see the character hitbox and frame data stickies) to touch the character on the ground's body (or "hurtbox") will hit the grounded character.
4.a You can't DI waveshines. If you could, various other wonky mechanics exist. So you can't.
4.b I don't know if you can SDI a shine off-stage.
5 Both get-up attack and roll provide invincibility frames. Invincibility frames are the white flashes you see on your character.
