If I would be thinking of actually trying something like this I don't think a complete change should be allowed each round. Maybe allowing a 1/3 of points allowed to be changed. Being able changed the whole abilities of the class seems a bit over powered.

You are probably right Skill increase is right out the window. And you have to remember that you will have the ability to assign your attributes points. You might also have to take out the increase the attributes points that is also a very high power thing for a character.