Hm, in the first part you simply repeat the findings in my post of 1 Jan. But I am interested in the second thing, because I have tried and failed to establish a connection via USB to my GPRS phone.
The phone can connect to the internet, and on the PDA I entered all the settings on a new connection under Windows Mobile 5 including a special modem character string. It failed, and a long call to my ISP's technical support did not come up with a solution. But you have prompted me to try using E2C in this case.
On E2C I set up a new GPRS/GSM destination, connect the phone via USB, then try, and fail, to connect from within E2C. Unfortunately the LOOX N520 does not have Bluetooth. I suspect the USB connectivity is defective.