I want to lay out the sample deal structure; something like the below, where I would be party 'B' and my investor would be party 'A'. 

We had already blown open the entire main floor layout, with a header, large center island, and now we vaulted the adjacent living room ceiling to 20’ high at its peak.

Although HOAs can be a pain in the butt you can make them the bad guy when enforcing the rules If you will househack w a SFH make sure its a good layout if you’re planning to have roommates.

If you have an 1000+ sq ft 1 bedroom unit that could play as a 2 bedroom depending on it's layout of course, but it wouldn't feel cramped.

They are very efficient (more so than baseboard) but again not knowing the layout it's impossible to guesstimate.

I come across some weird/outdated home layouts in my business.

Very briefly, introduce yourself, explain why you’re writing and clearly layout how they can get in touch with you.Not always, but I often find homeowners in this situation aren’t the most professional or put together people.

You have a ton of time, just take good pics, post it everywhere, take some video to give prospects a better sense of the layout/flow, and don't worry about it.

Any TK provider worth your time will be more than happy to lay out their numbers and walk through any and all calculations - and that's probably the most important thing to look for.

My other thought was to keep the layout as is, and use the efficiency as an air B&B.