Some questions on my nb caster build

lathbury

I recently gave in to the pressure and converted my dw bow nb to a caster one. I do still have the gear and skills for when stamina gets some love.
However I have some questions regarding some skills I'm running resto staff for single target with funnel health, crippling grasp, inner light and impale happy enough with that but for magika regen do I take siphoning strikes or spell symmetry? I'm in two minds and neither seems to enable me to hit the fabled 800+ dps.
could be l2p so if somebody knows ways to improve the rotation which I have let me know. My rotation is as follows cast inner light> crippling grasp > funnel health x4> grasp >potion. Repeat obv weaving la and if not using syphon throwing in symmetry as and when.

Next hopefully is easier aoe I have destro staff with inner light, siphoning attacks, sap essence, elemental ring. It's the last ability I can't decide on should it be refreshing path, volcanic rune or unstable wall of elements?
The way I say it path makes me mobile crits on dots and hots so builds ultimate and adds some of the self heal missing off this bar.
Rune gives me cc that is completely missing on this bar.
And unstable wall again gives crit ticks on dot and a nice whack of damage.
Obv I'm soft capped magika and running as much spell crit and damage I can get my mitts on.

PBpsy

For the single target rotation do you have: resto staff on with 2x cycle of life, 3 spell power legendary gliphs on your jewels, highly overcharged magicka from gear and food, full pvp bonuses from a campaign dominated by your faction(They forget to mention this most of the time when talking about their awesome dps),legendary resto staff with crit and legendary unresistable damage glyph, and do you flawlessly animation cancel?

I kind of prefer still going resto for AOE and just use sap essence and Veil of blades for damage.Since impulse needs weapon damage and I use spell damage jewels I can't get it to full potentials so I don't even try. I do more than enough damage already and I stay at full health from the Sap which also has great ultimate return. I actually like to have ambush on my AOE tab when solo. I use it as an interrupt for those pesky Archers and Healers and it's an Assassination skill so I get the Assassination passives.

Lynx7386

Siphoning attacks is a godsend for this build. If you do the strife -> resto light attack (or destro even) -> strife to clip the animation, with siphoning attacks active, you can keep that rotation up almost indefinitely, and the single target DPS is pretty up there. For more dps you can throw in some dots like cripple or entropy, but I dont usually have space for them on my bar.

For AoE you can either do what PBpsy said with a resto staff and sap + veil, but I find that the damage output is much higher using a destruction staff with sap + impulse + veil. Sap essence is there as a heal while doing AoE, and to use once every 30 seconds for the damage boost it gives to your impulse spam.