Is it possible to play from one account on other region servers

So two things:

First, every character can learn every crafting discipline. You won't even lose progress. The catch is that you can only have two active discipline at once (as in, can craft things with them), and it costs money to switch between them, based on how highly skilled a discipline you're switching into. (If you switch in to a discipline you have no experience in, it's free!)

Second, most untradable items are, in fact, account bound, so you can freely store them in your bank and remove them. I assume the actual Legendary Weapons will bind to a character, but the materials can be passed around willy nilly.

But Crafting in Guildwars 2 is very much its own part of the game. Crafted gear is equal to gear earned from any other number of options, and is not inherently better. The only real "perk", if you want to call it that, comes from convenience.

You can play on whatever server and region you choose. Once you're there, you can create five characters on that server. That's it.

You can't have multiple characters on multiple servers. You can transfer from a server to a different server in a different region at any time — for a cost. That's what the game tells you when you join a server for the first time, anyway.

I'm in Italy and have played the free weekend on a US server. I never felt lag getting in my way, but then again I kind of suck at MMORPGs...