Is a high skill value ONLY used to get past the requirements to buy perks or does it also affect your ability ?
Say if I have 70 in one-handed weapons, will that affect my abilities to fight better than if I would have skill value 10 ?
As I understand it right now, unless you buy high level perks you have no use of high skill values except to help raise your level (which don′t affect the particular skill).
I don′t find any answer of this in the help menu or manual.

Thanks in advacne for anyone who could shed some light on this

Yes. It does, however, effect different skills in different ways. Magick skills reduce magicka cost, for example, with combat skills increase damage. Enchanting increases enchanting power, same for smithing, alchemy, etc.

So Yes.

Thanks for your reply. That was the answer I was hoping to get. A pity there is no description for each skill to tell what will be improved.

Does the bow skill rising increase damage?? Probably obvious but I wanna see it in text .

Yes, the same for bows