Are the Collector’s Edition items tradeable

No, if you read the description of the salvage kit, it tells you the percentage chance for it to recover upgrades. The best non-gem-store salvage kit has an 80% chance to recover items in sockets.

Here are all the salvage kits:

Crude        - "small chance"
Basic        - 20%
Fine         - 40%
Journeyman's - 60%
Master's     - 80%
Black Lion   - 100%

The Black Lion salvage kit can be bought from the gem store for 300 gems, and can also occasionally be found in Black Lion chests.

Source

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.