You need a good handle on the big dollar costs such as electrical mechanical and structural. 

The mechanicals​ and layout were in great condition, it just needed a facelift.

I would also check any contract you've had with your agent to see if there is any language giving them authority to provide direction on your behalf to a contractor.If the contractor truly acted on their own and is still threatening a mechanics lien, I would talk to an attorney. 

I'm mechanically inclined and was looking for a truck in the 3-5k range that is easy to live with and can seat 4 comfortably (for when my parents come).

Also make sue you fully understand the new mechanicals you may need to install and their price tags (sprinklers/Fire monitoring /etc)

Currently I remodeled one unit and all mechanicals too.

I do a lot of BRRRR’s and just make sure to update all major mechanicals and fix structural issues before throwing a tenant in there.We are flipping a house that’s probably 100 years old and practically rebuilding the whole thing.

I even have another house that I'm itching to pursue, but I want to get the mechanics of all this down a little more before I do.

NFCU is probably a perfectly fine place to learn the basic mechanics of the job, so take their $20k/hr for that.

Every HUD property has a PC report (property condition report) which states what mechanicals have been tested and if they work.