re: P trap help - how would you repair?

The top left is a slip OP, it moves up and down with a washer. Yes you could cut it all out from where B hits A and go 1.5” that whole way with an adjustable p trap kit. That’s the way 95%+ of homes are done.

Work your way from B back to the sink making sure everything is solid. Then make the final adjustment at the part above C.

PS- you already have 1.5” drop from the sink so going wider after that is pointless as that’s your bottleneck anyway.