I never use my alias for reviews.  Most guys use their handle for writing reviews.  If you are going to write a bad one and do not want the provider to know who wrote it, use your alias then. Otherwise, just use your regular handle.  

I don't think you can PM from your alias.  To send a PM, you click on the envelope by someone's handle, and the blank message will open up.  Type your message and click send.  That's it.

Swim

Just click on "Mail" above and it will take you to your mail section from which you can PM, etc.  As for aliases, lots of guys do not want to be connected easily to their reviews.  So, while they may review under their handle, they only come on the boards with their alias.  The problem with this is their credibility as as poster suffers.

Also, if you write under your real handle it is easier for providers to read your review and decide to whitelist you.  If you use your alias they can't whitelist based on reading your review.  They would have to separately get your TER handle to whitelist you.