I also started to realize that there was no equity component to my strategy.

Every time you pay your mortgage, that new balance is reported.However your score can change even with information staying the same as a component of your score is the average age of your accounts.

Am I correct in assuming that another requirement is to have a certain amount of cash reserves saved up to cover any unexpected expenses?

His first purchase was a SFH and he feels good that he broke even selling it after an unexpected move out. 

Financing is just one component of underwriting a deal.

It is not going to get any better and if markets adjust or you end up with a bad tennat or unexpected capitol expences or another special HOA assessment you will be kicking yourself for not selling now.

That happened totally unexpected with having those medical problems but I am still hoping that that will pay off someday.   

Some common mistakes are trying to go cheap, not vetting out contractors, paying contractors too much up front, not having contractors sign a contract when you accept their bid, not having enough of a cushion for unexpected repairs (there will always be something)

@susan @Susan Little I agree about staying away from foreclosures as they can hide some nasty surprises from costly unexpected repairs to undisclosed liens.  

But the best way to get this as high as possible is to at least update something in all the major components of the house