ToME: the Tales of Maj'Eyal

I'm a donator and I seem to be stuck in somewhat of a rut. I can't seem to progress too much further than level 15 to 20ish. I know I am a noob.

I'm eagerly wanting to play some of the other locked races and classes and saw that you can play in exploration mode with unlimited lives. (I know it's not intended to be played this way but I REALLY want to see some new content.)

Can I unlock the races and classes this way or only through Roguelike/Adventure mode?

As far as I know, unlocks are possible in exploration mode as long as you play on normal (or insane, but that seems a tad counterproductive) difficulty. But of course, it would be easier to just edit the file with the allowed builds