No matter what happens, I plan to do up a formal contract with lawyer oversight.

You do not have to formally structure it as a partnership or form some business entity like an LLC.

Up until this point, I have done nothing formal to establish a new series each time I purchase a new property. 

If there are multiple listings in that area without permits, then there is a higher likelihood of there being no formal permit process.

Most investors in todays market will move on a deal without a formal inspection/appraisal.Best of luck.

The above comments are good input, but there some banks that will do construction loans based on the merits of the project (as constructed value) rather than your income. you will need to write a formal proposal (but i assume you did that for your previous loan).   

In this market taking a contractor and getting a formal bid to make offers is not feasible. 

Legally he can’t evict me because there was only a 30 day notice (which started and ended while I was out of state), and the formal eviction notice hasn’t been posted or mentioned.

Can I set up some sort of agreement or promissory note that formalizes this properly? 

UNLESS the lots were formally combined and lot lines abandoned then they would need to be re subdivided.