Hi, I have an 8700g with TM and love it so far! I also work for a small company so we are not on BES. I have an earthlink email and it only took me a few minutes to set up. I have a MAC computer at work and though I have downloaded pocketmac for bb (it was free) I haven't even used yet. I was not concerned in syncing my contacts at this point.
However, the way it works for me is that if I get an email to my BB, it also goes to my Entourage email account on my work computer. If I want to delete an email on my BB I have the option to delete on my BB AND email account it will OR I can just delete on my BB and it will still come in on my work computer when I receive mail in Entourage. It will come in as an unread message though, but again it hasn't been a problem for me.
Sent emails from my BB do not get synced to my Entourage but that hasn't seemed to be a problem for me. However, there may surely be a way to do that I just haven't checked. I don't know much about IMing as I don't use that.
You will LOVE your 8700g though. Be sure, when you're settled with your BB, do download Berry 411. It's so cool, you look up a restaurant, etc. it gives you an address/number and you can call right there. No need to call 411 anymore. Lots of other cool features on the BB too! Good luck and enjoy!!
'I am stuck on Blackberry and my Blackberry's stuck on me'