-Nexus will never get 4.0.3, it's going to upgrade to 4.0.4
-google voice is the be all end all, and actually just updated (see above few posts). no reason it shouldn't sync with your phone, just make sure your phones google account and the gvoice account are the same, and that the number for your cell phone is added in gvoice.
EDIT: do you get voicemails in your gvoice account, i.e. have you forwarded your voicemail from ATT to google yet?
-smsbackup (if it's been backed up for android, not sure) will back them up to gmail, however it doesn't restore them as far as I know. I'm sure someone else here has another solution.
Check out the tuna thread:
http://www.neogaf.com/forum/showthread.php?p=36268235
Also, the new ICSbrowser+ has gestures I believe, which should mimic the 'go to top of page' functionality you're missing. Also the tuna is not very loud, that'll hopefully get fixed in 4.0.4.
Whoa you knew my friend too?