I already own a 2 family house in the Boston area so this would not be first time home buyer. 

Are all of your current properties performing at their best without any potential cap ex coming?

I am a first-time home buyer.

Meanwhile, sellers—who are often buyers themselves—responded to rising mortgage rates with some caution.

@David D.Investing in real estate is a business and buyers and sellers make irrational decisions. 

Anglers and buyers need to remain alert and the more time the bait is in the water (at the right place) the higher chances of bringing home a delicious reward. 

The other factor with this: I think many (not all) of the buyers today that are going in with negative leverage (artificially buying down a short term rate cap does not create positive leverage) are going to be in trouble.  

Celina, Prosper etc.Which suburb holds the most potential for faster growth (in 5 to 10 years)?

There are several housing grants available for first time and qualified home buyer's.

I'm not sure about Pennsylvania but in my state it's caveat emptor/ buyer needs to do their own due diligence.