How do collections work?

I am a returning player to the game, having stopped playing after The Dark Below. I'm interested to know how the collections ingame work.

I have a number of items which exist in both my vault and also in my collections. I'm unsure of the mechanics.

Do I need to specifically add shaders, ships and emblems to collections? If not how do I add them? Are they added automatically? Or do I need equip them? What things can be collected?

Once an item exists in a collection is it safe to delete it?

Shaders, Emblems, Ships, Sparrows, Emotes and Exotics can all be collected.

Those you already had prior to the Taken King patch will be added to your collection automatically and newly acquired items will be added as soon as you receive them. You do not need to equip them.

Once an item is in your collection, it is perfectly safe to delete it. You can visit the appropriate collection kiosk and pick it up again at any time for no cost (apart from Exotics).

Exotics cost an Exotic Shard and 2500 Glimmer to acquire. Year 1 exotics which you have unlocked which have a Year 2 version can be bought initially for 150 Legendary Marks after which can bought again for an Exotic Shard and 2500 Glimmer.

Any Year 1 Exotic you acquire, which has a Year 2 variant will automatically be unlocked for you. Year 2 Exotics which you acquire where you don't already have the Year 1 version, the Year 2 version will be added to the collection, and the Year 1 version will remain locked.

Hope that helps.