I upgraded to FTTC about 6 weeks ago and have the Zen-supplied Zyxel VMG router. In response.
1. No. You need to edit / configure a couple of items, specifically the WAN profile for VDSL, plus your Zen user name and a VLAN, and you can set up your own wireless SSID and password. Details are provided with the email that comes from Zen but you can find them
here,
2. Mine is a 810D, the upright one. You may want to upgrade the firmware on delivery. The latest version for that model is linked below (install at your own risk! But it worked without problems for me).
Router Firmware
Good luck!
ZeN