There's a lot to answer to make that kind of decision and ultimately, it comes down to personality.

I still have a lot to learn, but what are the biggest pros and cons for investing in SFH 2-4 units and MF 5+ units? 

This may be difficult because you can't bring a whole lot to the table yet.

Now we are kicking around the idea of adding an ADU at the back of our long narrow lot to make room for a short term rental.

Wow, that's a lot to think about. 

All of these points don't have a lot to do with RE values, but rather overall Macro Economic health. 

Pittsburgh is affordable to live in so it draws many professionals seeking a city that has a lot to offer...that youthful vibe that is so appealing!

I realize that is likely far more conservative than many investors but I don't think prices will rise much in coming years so my focus is on paying the bills not hitting an appreciation jackpot.

there's a lot to consider.what type of preparation are you doing?

Those things do not cost a lot to do.