We get approved for the loans and everything and get ready to secure our down payments and hit a brick wall every turn.

The attorney should approve the next steps before going forward.5.

Is it wise to pay all cash for under market deals or should I get pre approved and finance something at a low rate with less cash up front?

It will likely subside over time.If this person has poisoned the pool and her friend is going to be equally problematic, you may want to non-renew the friend too.If "plans to do so more often in the future" means she is moving in with the "friend", then the friend has violated the lease by allowing a non-approved resident to live in the unit.  

I will be turning 18 in a couple of days  I only have 4 months of solid work experience so far, what is another way I can obtain a pre approval letter for hard money with limited history in work, and no experience in real estate?

Current rents are at $1000 for the front downstairs unit, and $800 for the upstairs unit, potential $800 for back bottom unit.I'm thinking of offering $225k being that it needs some work, flood zone etc...I have a pre-approval from a hard money lender for $200k, $100k Heloc, and $90k cash.

It gets tricky trying to get approved for a primary residence if you are currently utilizing one within a certain radius.

Also, buyer's were informed by their lender that their loan is about to expire so they would have to be approved once again.Buyer has 3 little girls all in grade school so you can imagine the stress and inconvenience this has caused them. 

They will look up the zoning district that the property is in and see if a 3 unit building is an approved "Use" in that zoning district.

Every operating agreement has things like roles and responsibilities, who can make certain decisions on there own and what decisions need approval from all or part of the rest of the team,  what the holding period looks like, what happens if someone wants out etc...