Thread: harry potter and the half-blood prince (ps3) help!

Dear friends, if someone of you played to Harry Potter and the half-blood prince on ps3 ( but also other consolles or pc will be the same I guess...) can answer the following questions:
1) There's a quidditch bonus unlockable, but seems impossibile to unlock, even getting 5 stars in all the quidditch challenges: how to unlock this quidditch bonus?
2) potions : even making a potion without problems, I never get 5 stars, I get all "goods" and 0,1 or 2 "excellent". how to obtain "excellent" when making potions?
p.s. of course I already collected ALL crests and minicrests of the game!
thank you!