You do gain access to the elite skills at level 30, and can have more of you utility skills unlocked at once at 5/10/15, but you have access to the same ones once you unlock them, there is nothing stopping you from unlocking the last tier skills at level 5 other than the fact that you won't have the skill points to progress that far, but it is theoretically possible. Traits go a way to making up for it, often adding extra effects, with some only been available at the highest tier slot (I think that is level 60). but the effects of traits are to make complement your weapon with stat boosts, and other subtle effects (eg, I gain a few seconds of regeneration if my health drops below 75%, useful, but not amazing, but it's saved my life on more than one occasion, helping me last that little bit longer).
You use most of the same skills through the game, and it was intended like that, they wanted everyone to be able to do everything, but left a few restrictions in for those that like progression, but there are still some options you unlock as you level up, just not as many as in other games.
If you want to find out what classes are like later on, drop into the PvP, they bring anyone there up to level 80, and give you all equivalent gear (it's been said before, but I'll say it again, playing lots doesn't give you better gear, it gives you better looking gear), once your finished browsing the runes to find the set you want, and your chosen weapon, there are some targets around you can test them on. True, they aren't the best targets, but there are a a couple that fight back, again, not the best to compare to PvE, but it might help compare some of the options you get at higher levels. And I've said it twice already, not the best comparison, the enemies and skills available are only those used in PvP, and the challenges aren't the same, but it MIGHT help. And if nothing else, the PvP is also fun (depending on your point of view) and one the larger parts of the end game stuff.