Hello, from my experience I can answer your question. Your eq is actually cool, I had similar ones at your level. You have a lot of fire resistance in it, so as your next imbu you should put deth resistance in Ghost Chestplate and have Moon Mirror in the slot. Recently, new SUPER Stoic Iks boots have been added that give you 5% fire resistance, I recommend them. If you want to improve your character, you can also put a tier on your legs, the avatar does the job and the Fabulous legs have classifications 3, so it won't be expensive.
Before getting charms i recomend you not to box, monsters may die to long. After charms you can easly do it around lvl 450 and make bigger boxes in the rooms. Hope i helped you :)