I haven't had any problems whatsoever with PDANet. Speeds are atleast as good as when I had the VZW $15 tethering connection. And Verizon doesn't seem to have a clue I'm tethering now....or they could careless...lol
As for accessing eMail while tethered, why not use internet access to your eMail accounts??...
I didn't set one up with Verizon Wireless, but I think that you can still access your Verizon eMails thru the internet as well, no?