Just watch allot of twitch and youtube videos and I think it might be a hassle to go through the skill bars especially now there will be ton of new skills will be added due to source points and racial skills which are not yet added.

So maybe there should be a drop down for source points and racial skills or a new skill bar (above the original skill bar) will pop up if you have a source point to give a proper instruction to the player that you can use these skills. Though maybe for racial skills they might have a different UI instead on the skill bar maybe by clicking on themselves they may have icons around them of their special racial skills.

I am not sure how or what are the best way it will be but It seems I know Larian will figure this out as we might have allot of bars to go through if they are all added to the skill bar.

I believe they're quite aware of the skillbar issue and are working on a solution, and reworking a lot of the UI in general. I think it'd be nice to be able to put a permanent set up 10-15 skills as an optional sidebar, probably smaller than the one on the bottom, and then maybe expand the bottom one to contain 15 skills or so. That way you could have 25-30 skills available at all times, which is plenty for lots of characters and for most of early game, and then you'd probably only need one or two extra skill bars filled out at the bottom.

Or maybe you could have a button to expand your skillbars to show all your abilities at once, stretching to the right along the bottom and then going vertically on the right for a max of 40-50 skills, and it'd optionally auto-expand when you enter combat. Most people are willing to sacrifice a bit of screen real-estate for convenience.

Yeah I know Swen said on one of the videos that UI's will defiantly be changing.

I was also thinking about having another bar on the side and expand is not a bad idea as well.

Another option to make things slicker would be a pop-up menu like Divine Divinity had, so you could put categories of skills (Man-At-Arms, Hydrosophist) in the hotbar, and when you click it, up pops up a list of all your known skills of that type so you could select what you want from there.

Yep, I like that from Divine Divinity. Not related but there was also a nice feature for the potions where it was easy to access but yeah those pop up menu was great.

I aggree that pop up menus for each skill tree and potions may be a good idea.
In D:OS1 it was hard to cycle through lots of bars to find the skill you wanted.
It is nice when the game is sorting your abilities somehow.