I don't see how you could compare it to WoW at all (combat wise). Everything in Tera is active, half or more of the stuff in WoW is passive (my main in WoW is a rogue, I'd guess 80% or more of my damage is passive so it isn't just tanking). Tanking in WoW is essentially praying for RNG and that your healer heals you (longer cd's and threat aside). Your living through those swings has almost nothing to do with you. Now you do need to hit your cd's in wow, but hey, those are all passive once activated. Threat in WoW? Well, currently its almost passive as you can hold it without even trying. Threat in Tera doesn't last forever (theres a couple theories on the specifics) so you can't just build up threat and then take it easy, and good dps will pull threat with absolutely no warning so you have to constantly be ready to yank it back. The only time in WoW some one can really pull threat is in the first 10ish seconds and after a minute or more there is pretty much no way in hell any dps will ever pull it off you. Tanking in Tera is about actively mitigating the damage and not praying that rng allows you to dodge/parry/block enough. Even WoW's potentially new turn to things like Death Strike is just something you do after you took the damage, it still is passively sitting there and taking it.
Dps in WoW is pretty much just using a rotation and there is hardly anything you ever need to worry about other than what DBM/DXE will give you a timer for. Tera you do have a optimal rotation but you need to consider things like getting stuck in an animation (which would require you to burn your dodge to get out of) and you have to actively watch the boss.
As far as end game raiding in WoW compared to end game 5 mans in Tera, one of the other important differences is that when I play Tera I feel like I'm playing the game itself. When I raid in WoW (and I still am raiding with my guild in WoW 1 night a week to farm hm DS) I feel like I'm playing bar minigames just staring at my cooldown bar, energy bar, boss timer bars, grid if I'm healing and honestly hardly have to look at the boss or my own character that much (except when DBM timers tell me to, which could be argued is a decent amount). In Tera, you have to constantly be looking at your char and the boss or you risk him jumping over and doing some move that will trash you (or turning around and doing it if you are melee).