I would change your skill points around to look like this (Maybe could pick up BWC/High Potency like I said but eh, up to you if you don’t mind another skill slot being taken, it does help quite a bit though).
Most changes I made have been explained either by me or others above except for putting Static Strike down to 1 point. You’re not focusing on Lightning damage so you won’t see big returns if you invest into it with your build.
I would also start putting all of your points into Physique. You likely have enough Cunning. Late game, you want to use a Potion of Reshaping to respec your points and put enough into Cunning/Spirit to meet equipment requirements and dump everything else into Physique - you need the health and DA it gives for Ultimate.
Your devotion could be improved. Firstly, you have few defensive constellations (the only ones I can see is a few points into Behemoth and Lizard offers a smidge) and have gone heavily into offensive constellations, namely offensive procs. You might want to consider dropping some and moving points into ones that provide defensive procs or defensive stats, ones I can recommend are:
Defensive celestial powers:
Behemoth (Giant’s Blood)
Chariot of the Dead (Wayward Soul)
Ghoul (Ghoulish Hunger)
Crab (Arcane Shield)
It’s not perfect but I would probably do something like this for your devotion. (This link still has your current skill selections).
Changes I made and why:
-Removed Imp. Imp isn’t great really as far as T1 constellations go, even on Aether/Fire casters. Flame Torrent is much better for you.
-Removed Falcon. Falcon Swoop used to be a devastating shotgun that all builds took long ago but it’s steadily received nerfs to the point where it’s great for Bleed builds and probably Physical builds and ‘eh’ for everyone else. Basically, there are other constellations that will benefit you more than Falcon.
-Removed Lizard. Repurposed towards Eel for DA.
-Removed points in Hydra and Magi. Repurposed for other important constellations. OA and flat damage are earned elsewhere.
+Eel. As mentioned, provides DA and also some Pierce resistance.
+Chariot of the Dead. Provides tons of OA along it’s nodes, some other nice bonuses and a proc that will keep you up some more and provide a nice boost in DA.
+Ghoul. For some passive attack damage converted to health/lifesteal and also for Ghoulish Hunger - when it goes off you go into a life steal frenzy. As mentioned, Physical damage is deadly so the resistance to it is nice too.
+Completed Solael’s Witchblade. Eldritch Fire is a stackable source of resist reduction for Fire and Chaos. I have Curse of Frailty bound to it as crowds of enemies give it multiple chances to go off every tick.
+Quill. Some nice bonuses on here, we need it to get to Rhowan’s Crown.
+Rhowan’s Crown. For Elemental Storm, it lowers enemy resistance to Fire allowing you to do more damage. It also helps with breaking enemies resistance to Fire on ones where it is high. Bind it to Fire Strike to proc it as often as possible as it has a fairly low cooldown and decent % chance.
+This opens up Ulzuin’s Torch for which I have put 3 points in to start. Torch is amazing for it’s nodes but also it’s proc when you reach it.
After putting 2 points into Torch for Meteor Shower, I’m not sure where your last 10 points would go with your current gear.
Keep looking for pieces of gear that give resistances and if need be - stay in Elite and grind reputation with factions to Honoured/Revered for their Augments as they will provide extra resistances that you are missing out on and also for Faction gear.
Finally, sorry if that is a lot to take in, keep in mind that your new devotion skills will be starting at Level 1 so they might take some time to start rolling along.
Good luck and don’t forget to ask for help or assistance again if you still have issues or questions.
I just realised actually that you could pull a few points out of the Occultist mastery for 1 point in Temper and 1 point elsewhere (probably Hellfire Mine I’d say?).