The chances of you quitting your 9-5 and doing real estate full time and being successful is similar to the photo below where everyone at the top in the crowd is thinking they can do it, and there is one person for every few thousand that can do it. 

This tenant thinks he has 30 days, and hung up on me today, wouldn't take my phone calls after that. 

I guess I don't think of it as an investment as much since you're not putting any money in - it's just free money! 

You're income certainly isn't "normal" and some banks might shy away but this is a personal business and if you have a track record, I think you can find a bank to say yes.

I don't think you should buy this land. 

Some people think you can just move into a rental for 2 years and all the gains will be excluded.

Totally agree with @Chris Seveney- people alwyas think there's some secret tax benefit or trick if they do things like this.

For essentially one large slab/climate building I think roughly 25,000 sq. ft. is a decent estimate depending on set backs etc. 

I think he does a good job in vetting or teaching you how to vet.

My thinking was exactly the same as yours.