As to subclassing, I'm happy for the people who like it. From a purely commercial standpoint, it was a terrible decision. It will make retaining players over time more difficult than ever. Classes, when a game does them properly, feel very different to play. This is what truly gives players the freedom to play how they want. If they don't like the feel of combat, they can try a quite different approach by just trying a different class instead of a different game. By homogenizing everything, ESO has really shot itself in the foot for years to come.
If you make those pure class only, then your leaderboards are going to shrink even more, which makes it lose a lot of value.
With the introduction of subclassing PvP has been a total mess, but cleansing has gotten out of hand. Every build has now access to two cleanses (extended ritual and netch) which makes people that use restoring light and animal companions (vast majority) unkillable, unless they are really bad.
I think a way to balance that mess is to allow cleanses to remove only debuffs, such as minor defile, breach, etc. Since otherwise it cleanses all DOT pressure along with status effects that do damage. Another good way to balance mindless cleansing is to punish the cleanser for doing so, like making every DOT work similarly to how plague break does (cleanse DOT off and it does a burst of damage).
Currently there's too many cleanse options and all of them are over performing by a lot, so for the sake of balance something should be done.
I just wish they'd increase the duration of the Enchanted Lantern.