There are feeds for the Forum, I found your question
through RSS, if you use Feedly then all you have to do is either go to the main forum and copy/paste the address into Feedly, if you want certain part of the forum (I have the UK as a separate feed), then go to that sub-forum and do the same.
Whether you could do it for the PMs is another question, which I doubt would work, is there not an option for email notification of PMs, I know other Forums allow this