

You set the whitelist in Minecraft, and it uses your ID. I can’t remember exactly what Minecraft calls it, your player ID maybe. It doesn’t matter where you connect from then, as long as you’re logged in. I think it works the same way with pirated accounts too, but I haven’t got any here to check.
For the firewall, I’ve just been checking through the Minecraft log every now and then and banning the obvious bots and scanners, so that shouldn’t affect you either :)
Your account is less than a week old, and you’ve made about half a dozen posts around the same topic. Maybe try reading the answers to your questions and think about them.