The result of such an reward will be the spreading of "what's the best build ?
This will be the case in literally every game with skill/talent system [be it defined classes or classless design]. There is plenty of Divine Divinity guides in which you can read what skills are good and what skills should be skipped.
- THEN I want my own reward for non-sticking to ANY class & tree !
Your reward is versatility. You are jack of all trades, master of none.