I usually run with UPnP on and get 12 or more connections.  I noticed some crashing lately and had difficulty getting the wallet running until I turned UPnP off and ran with just three connections.  Things seem to be working now.  Perhaps there was a node that had some issue, I don't know.

Any staking wallet that has been staking on the same address for a long time will gradually start using more memory and CPU.  Your orphan rate will start rising too as the computer can't keep up with things.  The fix is pretty simple, I may post an article on Steemit about this.

As for the exchanges, NOVA was not accepting deposits last I checked but hopefully they will be back soon.  I hope eventually this coin will be on some decentralized exchange at some point, I think that would be good for PoS coins in general based on experiences I've seen with some exchanges (Cryptsy, etc.)