I've never tried this method, but a quick google search came up with this:
Setting up your Windows Mobile phone for Google Sync - Google Mobile Help
I don't think you can sync your texts from Android though, someone correct me if I'm wrong. I can tell you though that if you have a lot (like a thousand or more) texts, your phone won't take it well. I usually had to keep my inbox clean to keep it speedy and responsive. So I think that's possibly why your phone stopped working prior to Android. The email, GPS, Pandora, and Facebook usage won't be a problem on WinMo though. Although I would recommend staying away from the WinMo Facebook app, it's total crap. You're better off using m.facebook.com or touch.facebook.com.
As far as running Android, if you'd like to keep using that, I would say start with a fresh install. It's not uncommon for the build to just stop working. After a few weeks or so, I would also get the "process.acore" force close message and have to start over again.
Anyways good luck in whichever OS you choose.