An LLC is useful for two things: anonymity and legal protection.

While you can start with a written agreement, a professional document will help protect both of you, particularly in terms of ownership, responsibilities, and profit-sharing.

For contracts, consult a real estate attorney and use standard assignment agreements to stay protected.

She works part time because it's a good balance of her interests, and protection for the family.

If you are setting aside funds for capex, taxes, insurance, or other expenses that don't occur monthly, transfer those funds to Savings each month and hold them there until it's time to spend them.

A well written management contract should clearly spell out what is expected of both the PMC and the owner, to PROTECT both and avoid misunderstandings.

Seller should record their lien against the property, you both should have an attorney review to make sure all interests are property documented and protected, and i think everyone is in a good place. as far as evicting tenants... this is up to what you and the seller can negotiate. i would still be putting on the same contingencies - appraisal, inspection... know what you're buying. don't get blinded by the seller-finance piece. 

It is a protected class in several states...

Your proactive approach—especially the hurricane-proof renovations—really positions you well in terms of asset protection and long-term value.

So, I would be very conservative (for your standpoint) on the researched estimate.I would do what I suggested above, then if the tenant takes you to small claims court you explain to the judge the legislative time restrictions you were under in order to come up with an accurate repair expense.This is yet another example of how "tenant protection" laws, in practice, end up hurting the tenant in the end.