I'm similar to you. I agree on using a lightning staff front bar, because dual-wield has a 1m shorter range than Sweeps. This can be deceptive, e.g. you may hit a target with Sweeps while being out of range for dual-wield light attacks. I, thus, prefer the staff.

I also run very similar gear, e.g. 5x Deadly, 5x Whorl, 2x Nerieneth, Maelstrom fire staff back bar. Zaan parses better than Nerieneth and is said to be quite viable these days. I simply haven't bothered with it. Iceheart is on par with Nerieneth, as long as the shield holds.

I'll be honest, I don't aim to be the best dummy parser out there. Originally coming from a PvP and solo PvE background, I like builds that play well and that have some remnants of self-healing and sustain in them. Not only does that help when things go badly in a random group, it also means you're always ready to do portals in trials, where self-healing is usually needed, without changing the build.

My focus is staying on target and having that little bit of tankiness allowing you to do so in real content. My main DD is stamina Arcanist now, tbh. On that class I parse up to 93K. On the templar up to 85K. In real content, Arcanist is a lot better, due to the constant ranged cleave. The main content I do nowadays is vet DLC trials, non hard mode, mostly with random or learning groups. In those kind of groups my Arcanist is frequenty above average, e.g. doing significantly above 12.5% of damage, according to Combat Metrics, whereas the templar struggles to be average. The templar is also significantly backloaded when you look at trial logs and during parsing, e.g. the damage goes up significantly in execute with Radiant.

So much for context. I run about a 1 1/2 bar rotation. Skills are as follows. Front bar:

Puncturing Sweeps
Camou Hunter
Degeneration
Radiant Glory
Purifying Light
Flawless Dawnbreaker

Back bar:

Unstable Wall
Honor the Dead
Channeled Focus
Blazing Spear
Race Against Time
Shooting Star

Some notes on the skills:

• Couldn't tell you whether Camou Hunter or Inner Light is better. The former has +3% spell damage and some Minor Berserk uptime. The latter has +magicka. I suspect Camou is better.
• I've been trying other stuff instead of Degeneration, but surprisingly this parses well, despite - I believe - the trial atro giving Major Sorcery anyway. Maybe it's the slight added magicka. At any rate, I like bringing my own Major Sorcery and running tri-pots.
• Purifying Light is just impossible to get away from. Also the source of Minor Sorcery.
• Flawless Dawnbreaker is mostly passive, as usual.
• Blazing Spear is a flex spot. I like providing the Synergy in groups. In solo play and Infinite Archive I use Explosive Charge.
• Race Against Time is a PvP habit. I am unhappy without speed and snare removal. Barbed Trap is objectively much better, if you can be in melee range when it's up in your rotation. I don't like Barbed Trap. You can start executing from 40% on templar and you're naturally ranged at that point.
• Shooting Star is the ultimate I actively use.

Imo Magplar can be quite good, when it comes to Raid performance, because all the simplicity adds up to better awareness for mechanics.
Its not outrageously high damage, but hey, there are always trade offs.

When they made the last batch of changes to MagPlar, I talked to a guild friend MagPlar main on discord. He said basically MagPlar is fine. You have the best execute in the game and you are barely hanging on the backbar.

He used 2H Maelstrom, Dual Daggers Nirn/Precise for Deadly Strike and Whorl of the Depths. He prefers Nerien'eth in content, but says on a stationary fight Zaan is more DPS.

He uses Stampede, Degeneration and Vampires Bane on the backbar and the other two slots reserved for defense skills in content, mostly Channelled Focus and Repentance for sustain. Meteor as Ultimate. That's it.
Frontbar is Sweeps, Barb Trap, Radiant Oppression, Blazing Spear and Solar Barrage.

This way he can freely use his potions as he needs it. Ulti pots, Armor pots, Tri pots or trash pots.

Maelstrom 2H / Stampede, on the back bar, may be the most meta thing you can run in terms of damage (at least on a dummy). The reason I don't like it is that gap closer -> bar swap doesn't work properly, e.g. the timing is weird and it's prone to fail when used that way. My preferred rotation includes throwing Blazing Spear as I approach the target. I prefer to cast that first, with Unstable Wall, or it would be Stampede with 2H, into a bar swap. That, basically, doesn't work. You'd have to become very conscious about the timing of Stampede into bar swap or use a different rotation where Stampede happens earlier.