I understand most lenders will only lend with a traditional residential mortgage for up to 4 units only.

A single family rental has a conventional 30 year mortgage and usually a lower cash flow and traditionally costs less than its multi family counter part.

This makes your other checks that much more important and you may ask for additional items (if you don't already ask) like bank statements, tax returns etc.Be sure to look up local laws regarding how much you can collect upfront, quick way to get in trouble if you exceed the local max.  

This is how HOA comes into the game of this transaction.2) The existing HOA document has 80+ pages and is a scanned version (so not text searchable), I don't have time to read all 80+ pages and site down with an attorney to modify item by item to what I need.

You might save some interest if you get 10 or 15 people working on different items at the same time.

These are broad goals that need to be broken down into short term action items.

I see the lines between extended stay rentals ("LONG" short term rentals) blurring with traditional rentals.

I’m curious if I should reimburse her as those are items that while I could have taken care of at no charge to me I feel she should be compensated for her labor.

If you're doing a traditional long-term SFH, then I think 20% down would be best as that PMI will impact your cash-flow.  

Just some items to think about if you haven't already.Another note, if the tenant isn't still tied to a long term lease, it *could* be more favorable to a buyer and you may end up with a higher sales price.