Or should I have her pay me under market rent and then if she ever needs money for whatever I can just send her $500 on Venmo here and there.

They're good rental markets and certainly OK places to live, but definitely a step down from A or B+. but 

I never liked Airbnb's or VRBO's pricing structure because it seemed more like they set a price that will get you booked so they can get paid, and not necessarily for the profitability of your listing.

Your income isn't high enough for it to make sense as a rental and the closer you get to your residence limit the greater pressure you will have to sell it before losing your exclusion in whole or part. 500k right now can make $15k per year income with zero maintenance or tenant risks. 

At the very least, let it run for a year or two and see how it goes.

It could appraise based on rental income.You still can't sell or bundle your Airbnb or Vrbo account.

I'm trying to understand if the lease begins on the day of closing or the day after, if closing is at 2pm. 

And one simple question...Are you going to buy more investment properties, or invest in any way, in the future?

Answer sure.. have to check if there is a due on sale clause or if you have a PG to the orignal seller.. that mortgage stays in your name unless there is a formal assumption  Maybe the example is more challenging for a house as the property.Ex. with vacant land - seller finances to me $20k with 5% down and $1k/moCan I after 1-2 months, then resell the land to a cash buyer for $25k, pay off the original $20k and pocket the $5k?

I expect that means it needs to be 15 years or more.