At wich level can I start having my skills dubbeled ?
Two stars on short sword and two at shield and weapon style etc.

Depends on your class. Certain classes can never get two stars in their weapon specialization. Other classes can and then it depends on the class. For fighters, you get to pick another every 3 levels. For priests it's every 4 levels. Not to sure about rogues but it might be every 4 levels aswell. And for mages every 6th level.

JR

Damned i lost cousin Jan's techno gloves

oki .. but the class I was wondering about is thief ...

Well, i'm pretty sure they only get one star to put in their weapons specialization.

JR

Damned i lost cousin Jan's techno gloves

Thieves can only be proficient(*) in any weapon, and get an extra skill point for every 4 character levels.

The Swashbuckler however, can specialise(**) in any weapon, in addition to being able to max Two Weapon Skill(***).