You might want to save a shell for the CRP 50 quest.
For me, key things for inventory managing are:
1) Know vendor item locations (Iron Ore at Limsa vendor, Cotton Thread at Ul'dah vendor, etc) and only stock when needed or if it's used in too many things (like Rock Salt).
2) Sell anything that doesn't say "Crafting Material" and isn't used for the adventurer jobs.
3) Only convert raw goods if there's a single option (Gigantoad Skin -> Toad Leather). Otherwise, only convert when you need them (like with Rock Salt's MANY uses.)