It takes trial and error, failing and correcting, eating crap than having to get back up, but the best part is if your in it to really win it, than everything will just be a learning experience. 

Pretty soon you learn that success is not a THING that happens but a DAILY way of life and construct of doing steps and actions.90% of the population say they want success and wealth but when smoke and mirrors fades away and people see the real work behind it most go back to eating Doritos, watching movies, etc.I have had other real estate brokers tell me what I do is too hard.

Unless you hate the rental (I sold 3 of my least faves over the last 11 months) I'd probably keep it.Transaction costs will eat you alive if you sell every few years.

We have worked incredibly hard (7 days a week) and lived very modest (eating beans and rice) to save up $400k cash. 

From what you described the kitchen, bath will eat up the $100K already.

Even long distance REI in not practical because I work long 10-12 hour days and have just enough time to eat and sleep and do it all over again.

The make your own tongue-n-groove type, so when they start eating lunch with you , it means something. 

I would split the cost (or eat it and tell them to get rental insurance and email me proof).

If you failed to ask for the money up front you will eat it 10 times out of 10.

They had to rent a hotel room and eat out for a few days.