hey, i was wondering, is there any point in putting percentages, such as stealth over 100%??

Yes there is, although I wouldn't over-do it too much because you will miss out on the other thief skills. Having 100% in Hiding in Shadows doesn't mean you will will be 100% successful. Wearing any type of armor will give a -% to the equation. So having more than 100% will work to off-set the armor penalty enough to be close to perfect. I can't remember the details exactly, but heavier armor will give a greater penalty to your skills and there will always be at least a small chance of autofailure for some things like Hiding in Shadows.

Don't put it over 100% in anything unless you've got an XP cap remover. If you do put 1 over 100%, then you won't be getting your other skills too far.
There are other factors besides armor penalty. Daylight affects it too, and other stuff as well.

and on find traps and pick locks 100% will see you right for the vast majority of occasions (maybe keep a potion or two handy for those trickier problems)

yeh I agree with Armen, potions will always buff you up if you need a higher rating (and this is very rare with 100%) so if everything gets to 100% then maybe add to stealth etc as some are covered by potions.

Potion of Master Thievery, Potion of Perception, and Potion of Power are things you should always keep handy for your thief.