Mmm in regards to raiding and stress. It 100% depends on who you raid with. A super casual normal mode guild is not going to have the same level of stress as an AOTC guild, which is not the same level as a Cutting Edge guild.
Overall, my stress level with my guild is 90% low.
I think if you found the right group, you could do normal and even heroic. PvP I would stay away from 100%. Even when casually doing it, it is very easy to get stressed. Raid fights are scripted dances, pvp is chaos.
Rotation and talent wise, if I was not raiding:
I would probably take either predator or lunar inspiration. Moonfire is awesome for pulling mobs at a distance.
The next row really depends. Mobility, speed, or survivability. Personally I take wild charge 99% of the time because it is so versatile.
The next row is the same, Resto affinity for more of a healing set, guardian to survive, balance for extra range on abilities. I like balance, but I owlweave so it has that added value for me.
I am partial to mighty bash on the fourth row. It can interrupt uninterruptable casts if a mob can be stunned. But maim can also stun, so heart of the wild with guardian affinity could really up your survivability.
Row 5 talents all have a place. Incarn is probably the weakest of the three, but for open world content I can see using any of them.
Primal wrath 100% for open world. Brutal slash really doesn’t give much to AoE combat and it isn’t the worst thing in the world to not have it for single target. When doing content mixed between AoE and single target, I almost always go primal wrath.
Final row I would pick between feral frenzy and moment. Since you are necrolord I would lean heavily more towards feral frenzy. It adds a dot which I believe is buffed by adaptive swarm.
Rotation: Definitely do what you can to keep a good swarm going, especially if you have your legendary. If you are doing a quest or running from one mob to another, don’t hesitate to cast swarm on yourself to keep a 5 stack of it rolling. It buffs your dots, so keep that in mind and try to keep your dots up. Think of it like a priority. Maintain dots, maintain swarm, everything else. Don’t be afraid to spend some time on the target dummy.
Necrolord Feral is a lot more nuanced and difficult compared to night fae feral, but I really really love its playstyle. I’ve finally reached a point I can pull similar DPS between them in dungeons. However, if you decide to look into raiding, night fae is a beast for single target. Kyrian is also not a horrible choice if you get into group content.
I wouldn’t touch venthyr with a 10ft pole. Blizzard did not design that with feral in mind. We have WAY too much downtime to ever get enough benefit from ravenous and last I knew our auto attacks do not stop it from stunning us.
Keep your trinkets passive as best you can. On use trinkets just add a wrinkle of complexity that you don’t need. There are plenty of decent passive trinkets.
Legendary: For necrolord I would craft a circle of life and death. On a ring ideally. I would make it with Haste/Crit probably (I made mine with crit/mastery back in the first patch lol).