[Gear Check] What can I do to improve my gear?

Hi, you have assumed right that you should look for CC (crit chance), CHD (critical hit damage) and fire dmg. The order you should prioritise this is Fire DMG > CC=CHD. You should maintain a 1:10 ratio on CC and CHD, meaning for example if you have 40% CC you should aim for 400% CHD (this is usually how you spend your paragon points).

I see you are running a CA (cluster arrow) build, the cornerstone of this build is a Cindercoat as it reduces the resource cost for fire spells by 20-30%. You should spend your gems on this, most players level a monk for the cindercoat as Kadala gives you DH coats if you spend the shards on your DH. http://eu.battle.net/d3/en/item/cindercoat

You have a pretty nice Danetta's but you really have to roll a socket in it and get a CHD gem in it.

An item that is pretty much BiS (best in slot) is Reapers Wraps, its a very easily obtainable craftable legendary. You get this from farming Malthael. http://eu.battle.net/d3/en/artisan/blacksmith/recipe/reapers-wraps

You can get a really nice head from bounties in A3 Pride's fall. http://us.battle.net/d3/en/item/prides-fall-pgClp

Also the amulet you get from bounties from A1 is very good as it always drops with either CC or CHD along with other important stats. The ring from bounties A1 is also very good. http://us.battle.net/d3/en/item/ring-of-royal-grandeur-3qRFop http://us.battle.net/d3/en/item/golden-gorget-of-leoric-1I0CCL

Your magefists are pretty decent, I would roll CC on it, preferbly you'd roll AS to CC.

These are the things I would focus on at this point if I were you. Hope I helped.

More cc, roll sockets in crossbows with a green gem. You will increase your dmg output significantly with just more crit chance