roofers go by how many "squares" need to be installed... 

I had a slightly sturdier signpost that a roofer had used at my residence, so I ordered two single-sided corrugated plastic signs and attached them to both sides of that post. 

Even if I did, my cousin would also have to be a carpenter, plumber, roofer, home inspector, mortgage broker, realtor, property manager, black belt in aikido and fortune teller all at once for me to trust them enough to basically raise kids together.

You’d get a roofer out to say you need a complete roof.

But the truth is I don't go out of my way to meet the roofer or tile the guy.... they certainly can be useful to me or anyone I know in the future..

Every time I see a local contractor vehicle (roofer, electrician, carpenter, etc.)

Since the rehab work required might vary by the property - it's hard to know if you need a roofer, or a handyman or general contractor etc. 

I reached out to a lot of my surrounding municipalities this morning, most only require a licensed plumber and roofer, and don’t have a gc licensing program (Illinois doesn’t require it either), the others it’s just a small annual fee, no testing required, no bonding required.

I'm not the smartest guy in the room but I can make these profitable with self management and local relationships E.g. plumber, electrician, painter, GC, handyman, roofer... you get the picture. 

That's not to say you don't need trusted relationships with a plumber, electrician, roofer, tree trimmer, handy man, GC, etc, because life happens and stuff breaks.