We hired a GC for an exterior back wall stabilization.

You are "hiring" them to invest your money for you, assuming that they are highly skilled at purchasing operating and selling assets of a specific type. 

Bring an air compressor with fittings, hook it up, go around listening for air leaks.

Since I didn't hire them, I'm thinking I'm not legally responsible, is this generally accurate? 

If you just hire the cheapest or first PMC you speak with and it turns into a bad experience, please don’t assume ALL PMC’s are bad and start trashing PMC’s in general.

I think it matters more about asset class and expectations...if you are buying apartment complexes and hire a PM the has a portfolio of SFR's you're going to hate yourself at the end of the first year.

I dont think I will get into the short term rentals or air bnb. 

I think I can hire a realtor for some of the tasks above (showings to leasing) and an attorney for late payments follow up and evictions.

As I am also relatively new to property management, could you be kind enough to guide me on how to I find PM's looking to hire remotely.

I have a 4 unit property that has forced air heat but no a/c.