I spent about a year in NixOS, and my main desktop still has it, though mostly out of laziness. I did end up switching back to Arch, mostly because if there's anything you need that isn't in the Nix repos it's a pain to install. The other big issue I had was the lack of documentation, so you'll be figuring a lot of stuff out completely on your own, because Nix works differently enough to everything else that a lot of general Linux resources just don't apply.
If I had a recommendation for switching to nixos, I'd probably say use the Nix package manager on Arch for a while first, and just slowly switch everything to Arch. It'll get you more familiar with everything, and then you can make the switch more easily.
Often if you can make it past the first interview you don't get caught unless a workers comp claim gets filed. The place I work we had people * in training* come in smelling like weed, a few others smelling like booze, and one came in very obviously high on coke. From what I remember the only one who got fired was for cursing someone out. Even past that, we've had a couple of members of leaderships who were alcoholics who regularly drank on the job, and there was always at least one person smoking in the parking lot.
All depends on employee tolerance and employer need, really.