Remember, pro-formas are imaginary numbers, I've never had actual performance meet the exceptions of my plans.

I would do your best to form a good relationship with HOA presidents and members and see if there is any way to amend the bylaws for a very small percentage of units. 

You should probably read and understand their pro forma purchase contract before you win the bid so you understand the terms and conditions you'll be agreeing to when you sign. 

Instead of buying your new property we as the QI form a holding entity called the Exchange Accommodating Title holder (EAT). 

Typical investor presentations typically start with the projected overall returns, which almost any model will provide (in fact that is effectively the whole reason they exist), and often a hold period summarized pro forma, to show a bit more of the details that flow into your returns.Again, I think you should hit up Adventures in CRE.  

Build that into your pro forma just like you would vacancy rates, capex expenses for other rentals and you'll be fine.

The roles, responsibilities, contribution of time and money to the business etc could be outlined in an Operating Agreement if you form a new entity together.

Who would you recommend as a real estate attorney to form a series LLC in Texas?  

You just used the form a national service sells. 

The pro forma numbers are just that - numbers.