When I tell you that it can't be done under the GSL, do you think I might have spent more time than YOU did considering it? Maybe?
No, because you're clearly hung up on semantics. You can't rewrite class progression, big deal. Stop thinking inside the box that WOTC operates in.
You can define a class to have any kind of powers you want. Using that method, you can define a bunch of newbie classes, based on anything- you could even have one superclass with access to different powers based on the power source and role it's emulating. These powers can be flavored and built based on the newbieness of the classes- and the class can also have limited hit points, defences, ect, as well.
You could do all sorts of cool stuff- you could have a fear/heroism mechanic to add some depth, so that the classes actually do something with their powers. Maybe newbie classes only fight well if they're feeling brave, and they have to maintain their courage value in the face of scary monsters.
On top of that, you can use the existing mechanics in novel ways- maybe when a newbie PC gets bloodied, their player can choose to have them go unconcious as if they were at 0 hit points, but doing so gives the other PCs a healing effect or a courage boost.
The GSL doesn't stand in the way of that kind of design.
Now, obviously this thread makes #3 a bit more iffy. Perhaps there is a market for some of this stuff. But if there were, there would already be 3pps filling that market. Both Mark and I have said this. Don't believe us, ask more 3pps.
This might come as a shock to you, but we're none of us psychic and people are clearly still feeling out what is and is not viable to sell to 4e fans. You can ignore this as much as you like, but it's pretty obvious. Threads like this can help in that process, but only if they're positive and not weighed down with highly exagerated criticisms and that bit of circular logic you keep tossing around. Just because 3pp hasn't been that successful with 4e yet, doesn't mean it can't be.
Mark reverse patronage project sounds like an interesting experiment. Put your money where your mouth is. You say there is a market. Cause the product to exist and prove us wrong with its bountiful sales.
Actually I have put plenty of money into a product already, one which probably won't sell well, but I'm willing to learn from my mistakes rather than declaring the whole thing hopeless.