in the first vid, you started edgehogging game3, to force luigi to recover more on your terms, but kinda stopped. i think if you had supplemented that more with u/bair edgeguards, while edgehogging, it would've made things much simpler for you.
best example i can find is at about 17m10s. you get luigi off the stage, go for the edgehog, and refresh ledge invuln. luigi's clearly within uair's rear range, which has a low angle, and you just keep jumping. if you'd hit him with a uair at least once, you could've forced a much better situation for yourself. i think there were a few examples of this on the drac's game, as well.
overall, it looks like you give luigi a little bit too much leeway when he's recovering offstage. that might be due to lack of knowledge in that matchup and wanting to stay safe, since he got a lot of quick gimp kills on you from light hits at the ledge, but i think it led to a lot more tense situations for you overall.
edit: watching gf's now. holy crap, you make snake look easy. : o
against luigi, it looks like you should work on learning wavelands and sh-bair-wl, to be able to threaten more space at neutral.
a lot of the luigi issues look like it's matchup experience, not knowing when you can and can't follow up on stuff, which i can't help too much with, sadly. don't have any local luigis that i play often.