Q:
Can't Salvage, Can't Sell, keep or toss?
A:
You may as well just delete them.
Combining 4 of them in the Mystic Forge creates a new, random, piece of equipment which is most likely to be about the same level and rarity as the ones you put in, which means it won’t be worth much to sell and if you salvage it you’ll just get a few basic materials. Not really worth the hassle of storing them until you get there.
But just so you know you can reach Lion’s Arch (where the Mystic Forge is) at any time by clicking on the PvP menu (crossed swords icon) and then the button to go to the PvP Lobby, then running into the pink asura gate portal that will be right in front of you when you arrive.
This is also useful because there’s a bank, merchant and Trading Post NPC in the Heart of the Mists (PvP Lobby), and if you use the menu to leave instead of the portal it will take you back to the map you were on.
“Life’s a journey, not a destination.”
I’d just toss them, you’ll only get a few silver in material prices.
Items you can’t salvage or sell you can just destroy instead, by dragging them out of the inventory window. Confirm that you like to destroy it.
There are level thresholds for qualities:
14: masterwork
39*: rare
63: exotic
(* You can craft Lv.35 rares of iron/wool/thin leather, but naturals don’t happen until 39)
The chance of getting a higher quality won’t happen if the resulting level of the item is lower than the threshold for rarity, e.g. 4x masterworks that spit out a Lv.36 will ignore chance for Rare.
The Guild Wars 2 wiki has more info, use “Mystic Forge” as search query to get the page.
Part of the [PORT] mystical tour – “Marilee Mangletooth.” What main?
Something something Autechre fanatic.
Also be aware that some items which you receive from karma vendors or as a leveling reward cannot be used in the mystic forge (I’d link an example but it appears the API is down).
Anet blocked these items from being “useful” after you’re done with them so that people wouldn’t just roll new characters to get easy loot/mats. Sometimes the only thing you can do with those weapons or pieces of armour is destroy them.