@ OP ... to be honest, I would not have a clue how to help you, but it seems you may calculate other things differently to the sheep.
No worries the build is doing well so far. I just figured maybe somebody comes up with some other ideas.
Your Helm... Flickering Flame... is this the ONLY option? Reason for saying this is to take the Pro's and Con's ... would a +2 skill (xxx) helm help? (this is based on increasing every skill by +2, thus maybe altering your skill setup)
There's never only one option and I'm considering every possibility I can. Flickering flame is relatively easy to come by. Everything else I'd have to shop and wait for auctions to end.
The biggest upside I see from flickering flame is not even the +3 fire skills or -15 fire res, but the fire res aura. It puts me from 2 fire res to 90. I'd have to use an inventory full of charms to have the same effect.
just following your gear setup.
Hoto + Spirit (+ more skills) and Pheonix on switch to use Redemption Aura (also another hoto or CTA) ... the Hoto + spirit is also Skill related, fcr and maybe more res.
Phoenix is absolutely great on fire sorc. The main part is the -28 fire res. Since fire sorc does not have access to -res from its mastery like cold, any -res are very important.
It comes with other conveniences as well, such as light and fire max res and a redemption aura which makes playing with it really smooth.
I do think that the only gear parts on fire sorc that are non-negotiable are magefists and phoenix.
NOTE: the Memory ES thing should be in your cube in your inventory if you need to recast... I don't see how effective it is?
Whether one uses a memory or a cta with +es skills is in the end personal preference. Yesterday I did pre tele in TZ baalruns and I used to switch cta with hoto to bo myself.
Armor... Vipers upped with perfect res and using 5/5 facet... hmm can the 5/5 be added some where else? Poor example would be Night wings helm, or a 2 socket Diadem with +2 Sorc skills / fcr or whatever random mods since it is PvM. Oh... maybe a Lidless Wall for fun.
Again Viper is an item that can be replaced. However it does hold it's own on this build with +30 fcr that are needed for the breakpoint and res.
i gave him the bis setup which isnt even expensive
The issue I have with the setup you posted is that the only source of resistance is viper.
Sure you can get res on any crafted/rare slot and charms, but even I don't think it's easy to max them out.
In the end it's a matter of preference. The current setup I'm using 1-2 shots most minions in 8p T96 except for natural fire immunes which might take 3-4 fireballs.
In terms of damage output your build does most probably perform best.