It might be, I don't know - depends on the BCD of the crankset I'd guess, but ...
TBH my approach would be only to buy things that are really what I want, rather than buying with a plan to fiddle with it immediately (if you see what I mean). Personally I'd just scratch that from the list, and be patient. Keep on looking.
Not really with 39t. The BCD is too big to get a 36 or 34t inner chainring. You will need a new chainset. Quite pricey with current spares
Look for bikes with 50/34 or 48/32 chainsets