If you're going for A Grade, where you want to be is more shadyside, squirrel hill, friendship, Oakland, mt Lebanon, Southside and Dormont.

I still have a rainy day fund so I dont need to squirrel away any of the $400.Now is it more wise to put some/all of the $400 towards the mortgage to build equity faster and potentially borrow against it later on, or is it more beneficial to keep the money aside to myself for future investments?

In other words, you can just take the cash flow now...or...you can double what you have now...by using your equity instead of squirreling it away.Equity is dead money, and 5 times more valuable outside of the property than inside it doing nothing.

All, Im having an electrical issue in a rental and the power could be down for days (The service drop from the point of attachment to the meter base is damaged in 2 locations from squirrels chewing neutral.

Those unplanned for expenses come quick and hard.

Either way I would recommend squirreling away money into a separate reserve account and be sure to put at least some of the profits during the better months into this as well.

If it was building related and paid, I did it on my days off so that I could squirrel money away for two things... real estate, and traveling.At this point, I had been involved in some small to mid range real estate deals with some older guys who were looking to get into the game, one of them became wildly successful, and I still consider him a mentor to this day.  

You're going in a good direction in life so we don't want something unplanned to set you "off course".  

We had to do some unplanned car shopping.

What I see is an accessible entry level property that could do one of two things: easily cash flow 2% as a rental, or provide a comfortable place to live and squirrel away the difference.