I think most skills should be revamped. I'm against skill spamming and think Light & Heavy attacks should always be main source of damage, and skills should help out in certain kind of situations.
For now it seems like most people play the game by spamming skills for maximum DPS, and making builds thereafter. In my opinion skills should be used for things like, survivability, burst damage, AOE, Damage over time, CC, and not for spamming as a source of sustained DPS.
I wouldn't mind if they increased both the cost and effectiveness of all skills so you can't use them over and over, and instead only use them when it really matters. I think that would make gameplay more fun and interesting, and you would learn when or when not to use a skill instead of hitting the same button over and over, because most people have enough magicka or stamina regen to do so. Skills should be powerful, and useful, and help you out in certain kind of situations.
I really dislike that kind of playstyle and I see a lot of people playing this way. Head in and just spam your main damage skill. Lot of AEO destruction staff wielders spamming impulse over and over, etc. for example.
A spell like Crystal Shard and it's morphs, is quite neat, but using it as a main source of sustained DPS ruins the whole thing. It doesn't really do much more damage than a Heavy Attack. Why not make it more powerful, but at a higher cost?
There is a lot of skills that can be spammed like this and doesn't make gameplay very fun in the long run.
For me a skill like impulse should be super powerful, but a one time cast, when you want to do massive ammounts of AOE damage in a certain situation. Not like a main source of spammable damage.
Defensive skills like DK's reflecting scales, is really useful and powerful, but i see people keeping this skill up almost 100% of the time and although that's really awesome, i don't think it is intended.
Anyway i would rather see skills being used more rarely but was more powerful in general. Recast timers or cooldowns, or increasing costs of skills and increasing the effectiveness of the skills would probably make the game more fun, tactical and challenging.
Maybe morphs of skills should have more variety. One powerful version, and one weaker spammable version, for those who like that playstyle?
Either way, right now there are some skills that are too powerful to be spammable, and some skills that are to weak to be useful.