Then if things get tight, you have the flexibility to reduce your payments.

My biggest concern is trying to find a smaller local bank or credit union in the area that is known to provide flexible in-house financing, so I can start building a relationship with them ahead of time while I save up.

Ideally, the line of credit would give you flexibility and you would only pay interest on what you had out. 

The terms of the note then become more negotiable - down payment, interest, amortization, etc.You or your agent may just need to inform the seller of their options.If you wish to go conventional there are options that may allow flexibility on the down payment such as owner occupying, asking the seller to hold a small second note, or simply showing the bank that it is a sound investment.

I'm pretty flexible where to live as my job can be remote, but am worried about finding a well-priced home to rent/house-hack.

You can do a UGMA, but UTMA will give you more flexibility later on, and additionally ask to set up a Roth IRA account for you.

Typically homes that are owned outright are better for seller financing since the seller can be more flexible in negotiating the deal. 

I used an attorney because I know some and they’re a little more flexible from personal experience.

You have a lot more flexibility.

You can definitely find these deals in the tristate area, you just need to be flexible with your situation.