The chains is the toughest part honestly. I like to have at least half a dozen for each saw. Get down to 1-2 sharp ones for each and then worry...
Yes an 038 for wood that’s typically 16” in diameter and smaller.
Nah the old bar is showing signs of significant wear as well. It’s more narrow than the new one by a decent amount.
Grease yes, too tight only on occasion but I will quickly loosen.
Yeah I dress the bar up from time to time but this one needs replacing. Has probably cut 250-350 cords.