If you want to build a damage-dealer or healer focused character, you need to focus on magicka or stamina respectively. Go with medium or light armor depending on that choice, appropriate weapon types, etc. A hybrid build will never have the same damage or healing output as a pure magicka or stamina build because of how the stats and champion points work.

The only time a hybrid build is functional is with heavy armor tank characters, primarily because damage output is not usually a primary concern. The versatility that comes from having full access to both of your resource pools is more valuable for a non damage dealer, because now you arent limited to just stamina or magicka for the bulk of your abilities. A hybrid gains the ability to pull from both pools to use a variety of skills instead of just one or the other.

But again, that only really works if you dont care about damage or healing, so it only remains a functional option for tanky characters. I enjoy playing hybrids myself, because I've always been one to pick the jack-of-all-trades/master of none type classes in RPG's. I'm hoping the warden really fits into that theme well for me when morrowind releases, just as my druid was in WoW.

The good thing with class skills, are they can be used with whatever weapon you have equipped. Usually class skills also gives the group something, like engulfing flames, nightblade heals etc.