I want vendors I can be lifelong clients of--improves our trust levels.

If there are no meet-ups in your area, consider building your network with a few trusted investors and RE professionals to create your own local meetup.Best of luck to you moving forward!

Never trust a site that looks like it was created on a $40 budget in a 2-hour time frame.

Your life will be a lot easier if you have a GC or even a Project Manager that you can trust.

My wife typically meets with them and we now have a set of contractors we regularly use and trust. 

Its trial and error unless you can get a referral from a trust worthy source.You can read reviews for cleaning companies.

Except for the vehicle of a delaware statutory trust (which are not normally thought of as syndications) you must be a tenant in common with the LP or LLC that is doing the syndication. 

As I don't have GC relationships I trust yet what is a reasonable amount of time from "hey I dont know you" to they show up and bid?   

The buyer should hire an inspector (with your direction) that they trust.

Yes but be weary trusting their statistics as they are algorithm based and we all know how well the algorithms worked out....