My magden is languishing. I don't really like the playstyle. It's a fairly tanky class, even in light armor. Magicka stacking seems to be the default, like others have said. I also find it a "buffy" class, e.g. a lot of stuff to keep in your rotation that you just buff, then you lash out with Deep Fissure and A.N.Other. No gap closer, no execute and poor mobility makes this a boring class. I feel very inward focused. A lot of the time you don't even aim at anyone, as you are either busy with buffs or casting Deep Fissure.

I have, in the past, gone for pure magicka stacking with Dampen on the front bar and magicka and health balanced just right to get an about 13K shield in CP with 50K+ magicka. That's probably still the way to go and Bright-Throat is not the best way to do it. With all the foods available, I'd go for Sugar Skulls or Disastrously Bloody Mara, foods that have a high stat-density. I notice you are using Disastrously, so that must work with Bright Throat's? Well, I was going to say use Necro + Alfiq + anything and everything that gives you more magicka, not spell damage. You want to be pushing 55K to 60K magicka with Northern Storm in CP. That Infused Spell Damage necklace, I wouldn't go for that. Use Arcane and all magicka recovery glyphs on jewelry. Some Swift, if you want to. If you need additional magicka recovery, use the Atro mundus instead of the Mage. The reason is the same as for magblade. It gives you better idle recovery and you actually feel that when you're standing on a flag and your build is buff-heavy, as magden builds tend to be. That said, hmm, Bright-Throat's + Mage Mundus is probably not bad, just your magicka seems low at 40K with CP.

I much prefer Bull Netch over Betty, because it sustains your stamina while blocking or sprinting, so that's where I get my stam regen. Never been that much of a fan of Shimmering Shield - I just use Dampen - but can understand the rationale for getting to Northern Storm quicker as would be using Bloodpawn.

Trellis is a great skill, because you can pump up your health underneath your big shield and it's reasonably cheap. It's better healing per magicka than Enchanted Growth. However, if you run dual or tri-food and some prismatics, Arctic Blast becomes competitive, so I've been trying that. I was running resto back bar, but wanted to try something different, so I currently respecced my warden to this:

https://en.uesp.net/wiki/Special:EsoBuildData?id=200761

That's just one variation and it's merely experimental. I had some duels with a stamden and I definitely felt more comfortable with Armor Master over Alfiq, but maybe I should move the shield back to the front bar. The big shield is definitely viable, but feels brittle if your resistances are low.

One reason to go for birds is that every animal skill heals you when it expires. So if Fissure + Birds are your spammables, you heal every one second. If you have Trellis up, every attack automatically gets offset by more healing. It's strong. I liked the idea of speccing into more health and trying Arctic Blast, but felt that setup was magicka hungry, so must have ended up shielding and casting that skill too often.

When front barring the shield, I used a vMA resto on the back bar in the past. Depending on your sets, you'll drop a lot of magicka, but it might be an option to consider.

Chudan on a warden?

Sorry, 2k spell damage (up to 3k with Balorgh). Those extra 450 were from when i was using the infused resto with weapon damage.
My lightning staff is currently sharpened but i'm thinking on making it infused and put the weapon damage there, but i kinda don't want to lose those 2.7K penetration either...