Rebirth System

Basically what I'm looking for is a Rebirth System like the one in the Disgaea Series

I'll Explain:

You start out as one class, you level up a bit. Then you decide you want to be another class. With the rebirth system, you get put back at level one when you change your class, but you get to keep a percentage of the stats you gained with the previous class.

This can be done with eventing. Just write your characters stats to variables. Divide them by whatever number you feel is appropriate, then change character class. Lastly change character's parameters increase by variable, and pick the variable that holds the stat. If i'm not quite explaining it right I can throw together a demo for you.

To me  that looks pretty much like Yanflys class script.

you could set it up exacly to match your needs.

But the idea with eventing sounds very good too

Gagay from GB Production did quite a number of Disgaea scripts. Sadly they are all for VX. You might still find them on the net and get someone to port the scripts.