He may have to eat those additional expenses if he can't prove he had approval prior to doing it.c.

If your rental income increases faster than inflation, you will have the additional dollars you need to pay inflated prices.

Planning to start a complete home remodel (interior/exterior) on a home (currently 837 sq ft), kitchen and bathroom bump out, and add an additional bathroom. 

I want to refurbish the entire house, including a complete kitchen and baths renovation, add an addition on the east side, new roof and siding, new flooring everywhere, paint inside and out"Then ask the GC to go over and put this into a more formal document.

I find single ADUs are mostly being added by people with minimal RE investment experience often without a clue as to the value that will be added by the adu addition.  

You may have to make modifications or additions in order to get that signed off.

Are there additional factors you think are worth considering?

I understand credit enhancements and additional guarantors are sometimes required but to be unable to cover escrow funds and to give away deal ownership for that service is kind of crazy but back to the main point, the real issue is when the Co-GP is not truthful about their true role or embellishes their portfolio/ unit count. 

The long term growth potential is driven by recent additions to the tech sector (google, intel, amazon, honda, and many start ups).

Here are a few additional ideas that have worked for me and others in competitive markets like Austin:Off-Market Leads from Contractors: I had a friend who rehabbed a house in North Austin last year.