Here is the main reason why... when you sell the property that's the last time you made money on that property. 

Private lenders are all pretty much stated income - we mainly look to see that your strategy/plan is sound and you have money in the bank to make it happen.

If this unit shares the address and the utilities with the main house then it would certainly be considered a 1 unit home. 

For tax purposes I made my principal residence 50% and rental investment 50%.

The  purpose of your contract will be to identify the price the seller is willing to accept, a deadline, and ensure that you can't be squeezed out.

I mainly looking to get into BRRRR properties or just buy and hold rentals for now but definitely would like to get into flipping once I'm able to move back to Pittsburgh.

If the partners agree to specially allocate one item (for example, capital gains) 80/20 for economic purposes per SEE safe harbor, the corresponding tax amounts must also be allocated 80/20.However, IRS has a framework that can reallocate the partnership items based on the “ partner's interest in the partnership” if IRS determines the method of sharing the partnership items lacks the “Substantial Economic effect” (SEE) To meet the SEE, there are strict rules to maintain meaningful capital accounts including Deficit Makeup Requirement for those accounts.With the requirement, the partner must at some point contribute sufficient capital to eliminate the deficit, and the partner has the burden of the loss that partnership has and the allocation of the partnership will be respected by the IRS.This is a very high-level summary of the rules and is not comprehensive. there are many exceptions as well.Since the substantial economic effect, safe harbor allocation rules are complex and requires considerable additional recordkeeping, it's easier to follow PIP standard. 

I think your purpose for getting into real estate is great!

You can definitely read books on rental properties in general, and maybe a little bit on management (out-of-state you'll likely be needing to manage the property manager as your main duty).While I can't think of books specific to it, there are still lots of resources.

The sole-proprietor LLC will be pass through for tax purpose anyway at the end of the year.