Hello, I'm a Glamour addict, and I need help.

This addiction is consuming my game play, and I want it to stop. So I've decided to go to my retainers and liquefy everything that isn't an event item or blue quality gear. So common stuff, greens, pinks, etc.

Before I do though I just have one question: Is it possible to "re-obtain" most of these items? Not through an item restoration service, I mean through conventional means. Can they be: Re-crafted, re-bought, etc? Most of this stuff is quest items from ARR and Heavensward, and the one thing really making me keep them is the fear the appearance is exclusive to that sole item from that one quest I did back 30 something levels ago.

Check the Calamity Salvager in any of the three major City-States, Limsa Lominsa, Ul'Dah, or Gridania. Those NPCs tend to have old quest rewards available for reclaimation at the cost of some Gil

special promotion items like the amazon event items cannot be re obtained once destroyed, all holiday event items however can be rebought from special vendors in the capitol cities near the calamity salvager, and most quest gear is just leveling gear that can be crafted

There is a really easy way to find out wether or not an item can easly be re-crafted and re-bought: Check the marketboard. If you can re-buy it there, you can, well... rebuy it.
Most of the ARR and HW quest rewards are craftable or, in case of the ARR, Ironworks gear that can be re-purchased with poetics. Again, an easy way to find out is to just check a website for a specific piece and see if there is a vendor listed.

Items that are tied to achievments - most of the event-gear for example, any gear that was obtained by earning an achievment in the first place etc. - can be re-bought at the calamatiy salvager

Ah, I had no idea about the Calamity Salvager. Thank you!