Using older versions of Outlook for Mac in business environments
Dan NB,
Mail is a bad product - I frequent the Apple Community Support forums and if there's one application that folks are going to have problems with, it's Apple's Mail. The problem with Outlook and Yosemite has been solved - by Apple - and you no longer have to jump through any hoops to get it up and running at this point.
I don't know what type you're having with Time Machine restores - that Office always asks for the activation key? That's true of a number of applications and, to my mind, is a great way to avoid pirating of the software.
Even if you do decide to give up Outlook - find something else to run other than Mail (Thunderbird, for example) - but there's no good reason that I can see to give up Outlook (and, yes, I run it both on OS X and Windows 7 Pro).
Good luck,
Clinton