do this more if you know the combo won't end well with you. not entirely restricted to corner, but more helpful in corner cases.
don't do this. if your health is high, just take the damage and see what happens after that. if your health is low, you can decide on whether to use the burst or saving it for next match. if you do the first option, you might end up wasting the burst by dying afterwards.
i don't even know why you decided to revolve your burst strats to rounds
this is bad, especially if the corner combo is not particularly a high damage one. save the burst for times when you REALLY need it, such as being in a corner combo where you know it'll do a lot of damage.
if you're winning, i'd save it. if you're losing, then by all means. just be careful of any burst baits.
i personally like doing this, but it sometimes backfires on me. be careful on when you burst in times like this.
generally, you'll want to be careful on which moves to burst. many moves in extend are safe on hit and allow the opponent to block the burst if done correctly (and there's always the hard burst bait). you'll also want to burst in combos that you know by heart will do a lot of damage and/or will put you in a clear disadvantage (such as Carl's unblockables).