I wonder if there's a proper way to rent out rooms or "units" without having to chop up the house and adding separate entrances and meters.

You should also check that the seller has proper chain of ownership of the mortgage.

Or do I just need to make sure that the contract is worded properly and protects my interests?

Thanks for your replies.Here is the TERM section of the lease:---------------------------Term: The term of this lease shall be for "one year" (duration) commencing 01-01-2019(date) and expiring at 11:59 PM Eastern Time 12-31-2019 (date (the “Initial Term”).Either Landlord or Tenant may terminate the tenancy at the expiration of the Initial Term by giving written notice to the other at least 30 days prior to the expiration date of the Initial Term.This notice shall contain a definitive move-out date after which the Tenant must have completely vacated the property.

The tenancy is held until they return the premises to me and/or a properly obtained and executed writ of possession from a judge sets them out on the curb.Your state laws may vary.  

Proper slope away from a house and gutter extensions can solve about 90% of foundation issues caused by water is what I have learned from my foundation guys.

Depends on the actual deal - you can make interest only payments for the duration of the loan or have an interest reserve account and make no payments until the loan balloons

Just give proper notice and go.You have a key, right?

I would replace the exhaust fan and make sure it is properly connected. 

Sometimes your desired data is easily accessible and in a proper format but more times than not you will get the run around in search for your data and then when you finally get it, you will need further assistance getting it market ready.