For instance, if you had a home in a nice subdivision with a 1-2 bedroom finished basement with kitchen, could you stay in the basement full-time (I'm a single bachelor) and then Air BnB out the entire top of the home?  

In that instance you are technically still the tax payer for the property. 

Did you change the floorplan (add an extra bedroom for instance)?

Couple reasons:1) More limited financing options.2) More limited use and structure for the deals.3) Finally, if you have to inject extra cash into the property for whatever reason (manage an economic downturn or natural disaster, for instance), it's going to be trickier using an SDIRA.Syndications and private lending protect you from much of the property management nuance.

A lot of things affect this in the shorter term, for instance if it is a well-built newer property, or has just been through a solid renovation, expenses should be lower for a period of time...maybe 30-35% of income. 

For instance, use the tax amount that the buyer might encounter vs what you have paid since 1999?

You can always make specific instances of payment for specific work products, again, each one should be in writing. 

For instance, I know a few shop owners, mechanics, restaurants, etc. and got permission to put my business cards on the cashier counter.As far as the numbers, if they work and you can see them working in the near future, then why not?

For instance the laundry room was divided into three closets and a very small “hallway” where the washer and dryer sat, so I took out some walls.

Always good for everyone to hear of these types of situations and to insure that when evaluating the deals, to understand a good reserve/LOC is required for just such instances.