Maintenance is a function of time and expenses.

It essentially pulls power from the unit that is not currently functioning.

If I'm using a partnership to purchase a property, how is the deal typically structured between both parties?

It’s easier for both these functions since they know us personally.  

I used the search function before I posted this, but somehow missed that!

If you pay them profit, they might look like partners in the deal, and you have to file a partnership return and issue K-1. 

I 100% agree with everything that Jay said but would add that if you are having trouble securing financing you could always invest your money with someone else either through partnership or syndications but it sounds like you have a pretty good grip on investing so it will make sense for you to do it yourself using the methods Jay mentioned.

However, if the LLC is part of a partnership or S corp business returns, all properties would be treated as a business versus rental income calculation.

Bought with Fully functioning (furnished) accessory dwelling unit with separate access currently covering ~70% of the mortgage.

Better yet, see if some degree of partnership on the deal can be worked out.