welcome to the forum
I do not have a Mac, but normally the game runs well on it I think. At the moment iOS and MacOS have been experiencing a few bugs. These are errors by Playrix, not the devices themselves.
Yes MacOS is now synced with iOS/Android/Kindle so you will be able to link your current game to a new MacOS.
We have a few members who play on Mac so hopefully they will be able to share with you first hand experience of playing Township on one