I meant do you have to have a tethering plan to use the laptop dock, I thought that kinda of silly considering I would only use one with wifi.
To use Firefox (or any internet option) in webtop you either need one of 3 things. #1 an AT&T data/tether plan for $45/Month, or #2 Wifi, or #3 Hacked your phone to enable tether without paying (it can be done but I do not want to get into that).
You can use the laptop dock without tethering, you will just get a popup saying you need to contact AT&T or firefox will not work, which goes away or will not popup if/when you connect to WiFi.
You can "hack" to enable tether on laptop but when AT&T starts cracking down on that, as soon as they peg you, they will just automatically add tethering to your account (change your current data plan to the $45/month for 4GB tether plan).
As long as you use Wifi and stay away from that hack, you will be able to use the
full webtop option with no additional charges. Even if you don't use Wifi, it will still work except the internet will not. You can still use the phone's browser in mobile view on webtop, so it kinda works on 3/4G.