Even if he wanted to seller finance the properties to you, he couldn't because the $100k first lien loan is still there and needs to be paid off (unless he is doing a wrap around structure which has its own hurdles).

.- full bathroom update x2-A/C RepairThose are the main ticket items

This is just a general question, but I see it discussed on here a lot that your rental properties are under a different insurance company than your primary residence (and other items) because usually your main insurance companies aren't great with investment insurance. 

That is one of the main reasons I wanted to get on BP.

I've been focusing my search mainly on things such as warehouses and retail.

What I mainly take issue with (okay, that sounds harsh) is that a lot of people are saying nothing in the economy is showing signs of going down in a ball of flames so we have time yet. 

The main thing to watch out for with any financing to the 401k is that you are not personally guaranteeing the loan.

Being an agent comes with its own set of hurdles and if you don't want to be an agent as a career it probably isn't worth the time and cost to get a license. 

Are population growth and unemployment rate the main two or there is more information I need to do homework on before investing in another market?

The main reasons are stated above but I can restate them.