No, if I want to play a rogue, I should pick the rogue class for it. I should not have to take rogue bits and stick them into my cleric.
I'll say it again: if you can stick bits from any class into any other class (which is what you had in D:OS), then your classes are fake and you have a classless system pretending to be a class-based system.
Argh, no. I loathe rigid and restricted classes. Let me be rubbish by being Jill-of-all-trades-and-master-of-getting-myself-pwned.