:37 there really wasn't a good punish tbh. I could have thrown the banana at him, but then he'd just fall to the ledge anyway. So the end situation would be the exact same only I wouldn't have a banana to assist with potential ledge traps. DB wouldn't have fully connected and he could have DI'd up to easily avoid the 4th hit (maybe even the third) and then have been in a MUCH better position to recover afterwards (gaining control of his character again, having his full mobility back, and having access to sideB again). I can see MK or some other character having good options in that situation, but anything I tried there would have been super risky and could have potentially reversed the situation.
4:40 was, unfortunately, just an input error. It was supposed to be a ledge hop to Z-drop, not a ledge jump =(
1:48 was admittedly basically just panic mode. Most grabs don't kill you (and even Diddy's shouldn't have if I had DI'd it better /bad) so I figured I'd rather avoid him going for his banana to combo me, fair, dsmash, and ftilt. The only option that popped into mind at the moment was shield so I did. I probably could have like... retreating nair'd or something instead but oh well. When anyone is at high percents, they default to shield a LOT and it's always easy for anyone to get grabs on anyone at that point.
To answer your questions though- I'm never confident in my execution and as a result I play, to the best of my ability, risk-free.
@P-3- I KNOW! It's SO good for so many characters. Marth just doesn't catch things. I can do it fairly well as Diddy and Snake and Falco. Marth and MK are just like... nope. Not catching this stuff. It's SOOO good and strong though.