We have looked at structuring the partnership as an LLC but our mortgage broker is telling us that this will prevent us from getting a mortgage or at a minimum result in a higher interest rate.

Unfortunately, most Sellers don't have a clue, they structure deals that are far more favorable to the Buyer, and they lose money when the potential Buyer walks away (over 80% of the time).If you're a seller, forget it and move on.

https://www.warreninspect.com/Warren Engineering is one of the largest inspection companies in town.I've also heard of Comfort Living Home Inspections, Kevin White. p. 585-802-6386I know someone with expertise in structural inspections and design if you ever need that specialty.

May answer as to what you need to know before you make an offer is basically "everything" with the exception of less than obvious defects to the structure or situations that need environmental testing.

Tenant ObligationsOne advantage of investing in retail properties is that tenants are typically responsible for their leased premises, and the landlord handles everything outside of the tenant’s walls, typically including the roof and structure.

I think how you structure it depends on whether you're using a listing service or booking clients directly.

I am looking for help on how to structure a partnership. 

How you structure the offer is crucial.

We need the building vacant before the structural repairs can be done.

I don't think you don't need any permits to add a bedroom/bath etc. if it's a single family home, you can arguably change anything within your structure (or outside but adding more structures/buildings needs permits).