I have to say the fact important NPCs are immune in ESO is very helpful. I remember in my first Skyrim playthrough I got caught looting in the Alchemist shop in Riften, killed all three people there, and forever more had one less shop to use. Since I also managed to not get caught while framing the Argonian merchant in the market, and he did actually go to prison, I seriously damaged my future equipment clearing possibilities in Riften...
Yeah I'm the same boat, my first skyrim experience I killed a chicken, had the town after me, killed who I could before dying then realised I *** up and restarted my game lol