Realize that a credit history is a reflection of one's ability to repay debts in the past, and most lenders will use this as a forecast of the investor's ability to repay in the future.

With your experience and ability to open a brokerage it sounds like you've got some great experiences to share and will be able to move forward! 

I'm not actually operating a business, just collecting rent on a single property, but perhaps that's splitting hairs...

Gives you the ability to learn REI as you go in a relatively low-key way. 

You'll need money or you'll need to have the ability to raise money. 

After he was finished with the roof and gables he sent us a bill for and extra $13k and said he could not have forseen the condition.

Essentially, the ability to have your purchase price + rehab costs less than 70% of the ARV, so after you rehab you can find tenants & then refinance to get all of your cash back.

The ability to buy rentals that will have equity, and you'll be able to learn the ropes in property management.

I will echo @Robert O'Keefe and say that management will give you a crash course to be able to transition into other things much easier than going in cold- but prepare to get some gray hairs and some 2AM phone calls.

My rental income covers all of my monthly costs, and the ability to maintain the lifestyle I was used to.