I did my best to play though the Clockwork quest line on PTS (Because I still enjoy questing content in the game but am way to pissed about balance, combat, and cheat engine decisions to pay one red cent more to this game.) Unfortunately, the stability of this combat is terrible even by ZOS standards. In particular, a variety of combat situations cause crashes to desktop. Some of these can by bypassed by simply bursting so much damage that the enemy dies before he casts whatever the offending skill is but this is not always the case. At the end of the key retrieval from the blackfeather court part of the main quest you have to activate a light switch during the fight when the enemy is at 60% or so. I crash 100% of the time at this point so the questline is blocked.

Other fights I had the same crash to desktop issue:
- Killing the little things to get the oil to present as a gift in the first quest (if they damage you it crashes)
- You always crash to desktop when in windup mouse form for one of the quests and you take any damage from the traps.
- Fighting a grievous twilight lord at one of those open world events causes a crash to desktop with his first attack every time.
- The boss you fight at both the beginning and end of the quest where you retrieve the traitor leader dude who had the key stolen from him by the crows. If either gets off a specific one of his attacks you die so they have to go down right quick.

Other issues I encountered:
1) Provisioning writs can no longer be completed. They all just say you don't have recipe improvement 6 when you do.

2) Enchanting hirelings deliver mats every zone transition.

3) Heavy / light attack scaling is broken (Has been since morrowind and half your raiders have quit but apparently not a problem.)
-Damage from medium attacks (partially charged heavy attacks) was nerfed 15% because they give back resources except that they don't give back resources.
-Damage from fully charged heavy attacks was not nerfed the 15% stated though the duration was shortened so they actually received a buff in damage / second as well as a return of resources. The damage now jumps directly from ~8k to ~12k at around 1.7 seconds on a fire staff when the medium attack becomes a full heavy and also returns resources.
- The animation for a fully charged heavy is still 2.2 seconds and has not been changed in two skill duration changes (it should be 1.7 seconds). It is also an animation that does not have any movement during most of it's duration so the player has no visual que for learning when a "fully charged heavy" has occurred and the player has qualified for the massive damage gain and resource return.

4) Wrobel still has a job. I can only assume that one of the fabricants has a short circuit that has prevented this from being remedied. Either that, or you have a Daedra infestation. Also, I tried to name my toon "Fire Wrobel"..... It was taken.

Anyhow, that is what I know so far about the bugs.