On the "Mighty Mouse" (which IMHO is far far from it) you just left and right click exactly the same as you would on any other mouse. It's just that Apple considers the buttons untidy and so has used touch sensitive pads instead. Read more here.
I'm struggling to understand your issues with Address Book. Within Address Book: to add a new person type Apple N (⌘ n) or click the + symbol at the bottom left of the contact pane.
Within Mail: Type a new address in to the To or Cc space then send/save the email. Next time you look at this message there will be a blue shade behind it and a little arrow. Click the arrow and choose Add to Address Book.
I suppose the gripe here is that within Mail you are presented a cut down Address Panel rather than the full blown Address Book application. Why not leave your views for Apple here after noting your issue I agree and so have duly whinged to Apple in this way myself.
kind regards
mrtotes
