I want the seller to carry the note the full term of the loan and I expect that interest to be reasonable and never change Your actually doing the seller a favor in many ways therefore I expect my back to get scratched too on the terms .

There's no better tuition than going through all the motions- coordinating with lenders and contractors, learning how to gut a bathroom and rip up carpet, having to deal with house inspections and code officials etc. 

You'll be an amateur landlord dealing with professional tenants where the rules are in their favor.

If you can convert your mortgage completely into a HELOC that could help your situation but it comes with major risks as well which you should learn before making any kind of move like this.One consideration, which may not be favorable, is to just consider renting if it's cheaper than your monthly mortgage now.

Zoe, this tenant did you a big favor.

There are a lot better ways to fund college in a tax favored environment than 529s.I can share more if need be.

Portfolio loans are more expensive and have less favorable terms so it puts more pressure on the cash-flow.

Also, add in motion sensor lights and/or dusk to dawn lights. 

To accomplish this without having to pay the additional foreign filing fees you would just nest the properties into land trusts.Land trusts are also very functional because they will streamline your investments for estate planning, add an additional layer of anonymity/privacy when formed by a knowledgeable attorney and allow you to retain favorable financing options.This is not legal advice, just  my opinion as a real estate investor.

Also learning how to not over spray and move the spray gun in an appropriate back and forth motion takes practice.