Hey guys does anyone know how to rename a Skill or an ActorValue in general?

thanks Phil

You can't rename the editor form of an AV.

Can you make a new one and mimic the effects of one?

Firstly: You cannot create new Actor Values or change their EditorIDs since those are hardcoded and what you see in the editor are just representations for reference.
Secondly: You can only change the in-game name for existing skills. That yields not much effect though since for instance you could make weapons level a different skill but if say you rename pickpocketing and associate weapons with it successful pickpockets still level that renamed skill. Only hope is that the people making/using SKSE figure out how to change these things and you can rely on this mod to change/add skills.