Not sure if I'm on the right path [Occultist: CwC Flameblast/Arc]

Hello guys, last year I got my hands on a handful of exalts and for once decided to not follow a guide and make my own build(kinda). So after after researching and thinking a lot I came up with a build that would use Flameblast with cast while channeling to trigger the skill Arc.

I thought it would be a good idea because of this ring:



While you are standing still channeling Flameblast you get pretty vulnerable, so I thought that having a skill that freezes and shocks might be a good way to defend yourself(also I always wanted to use a lightning skill and vinktars ;x), besides that since now arc damage will be both cold and lightning it might be a good idea to pick the elemental overlord keystone to boost Flameblast's damage.

Now after deciding that, I thought about building my character in a way that the damage would scale both skills, the only way I could think of was by picking some elemental damage nodes and a ton of crit chance and crit multiplier nodes, after all if you scale crit you scale both skills, and besides arc will now freeze and shock every time you crit ;D

Since I went with crit my weapon of choice was this one:


It has crit stuff and I was thinking about having two 6L, and going low life so I could have more survivability with curses and auras(which was possible since I had the money for a shav's).

Now here is where I start to have doubts. If you see my planned build you will realize that besides a lot of crit stuff, I also picked lots of "reduced mana reservation" nodes:



I was planning to go with 5 auras or something like that, and a curses on hit set up with 3 curses, but later I decided against since it would be bothersome to curse stuff every time, so I choose 3 auras (discipline, haste, and purity of elements), and 3 curses on blasphemy(enfeeble, temporal chains, and elemental weakness).

I played and reached lvl 81 with my occultist using this build, but somehow it feels like the character should be doing better than this when I take in consideration that I have 3 auras and 2 curses(enfeeble and temporal chains for now).

So, after feeding you guys with all this information(if there is anyone reading of course) there are a few things I'd like to ask:

1)I went Occultist for survivability and for the extra curse/power charge, but now I'm not sure if it was the best choice, Elementalist and Inquisitor seems that have a lot of synergy with this build, should I keep as Occultist? (making another character is not a problem for me if the difference in performance is YUGE)

2)I read on reddit, that cast while channeling makes more sense when you aren't planning on having any cast speed, if I was using something like scorching ray or incinerate I would agree, but now I'm using Flameblast. Should I go with or without cast speed?

3)Since I picked some nodes that increase the effect of auras I thought about having a vaal haste/grace/discipline set up, but now I'm really confused, I haven't been using them a lot (I didn't get my hands on vaal haste yet, I only pop up grace on bosses, and discipline I don't even use), so if my aim is to do late game stuff (like uber atziri and guardians) should I keep them, or replace them for a CwDT immortal call set up? I can keep one if I do that, maybe haste?

4)Assassin's mark or elemental weakness?


I think that this is everything I have to ask for now, I thank everyone that read so far even if you don't answer me.

My equips: