Recipes are classified and ordered by recipe level, not by item level nor by item required level. So there will be times when you're looking for a piece of gear that requires level 10, but it will end up in the level 11-15 recipe bracket.
The recipe level brackets are completely useless once we cap the crafting job, but it's very useful during leveling. There should be an option to replace the recipe level brackets with quick filter buttons like the market board, but better than the market board. For example these buttons should be readily accessible:
Intermediate Items: if you're BSM, clicking this button should list all the ingots/rivets from all level ranges; if you're WVR buy ffxiv gil, it should list all the threads and cloths; LTW, the leathers
Fighter/Sorcerer/Crafter/Gatherer/All toggle button: clicking on this button will toggle between the five filters, so I can quickly locate all the CP accessories on my GSM, for example
Job specific buttons: these buttons should dynamically change according to the toggle above. So click on Fighter, then on PLD, and I get all the armors available to the PLD on my ARM (but exclude the more general Fighter gear). On my BSM this would list all the swords. No more skimming though all the crafter tools when you're just looking for that weapon recipe.
Tier Up/Tier Down: for example my list goes Bronze Ingot, Bronze Rivet, Bronze Rings, Iron Ingot, Iron Rivet, ...; by clicking Tier Up, the list jumps to put the Iron Ingot at the top. This is extremely useful for GSM where each "tier" of materials you get 6 stat-related stones and elemental materials.
And a shopping cart feature would be nice, but that may be asking too much when we can't even manually disable tracking specific quests...