Tell new players which R/C combos are easiest
This is a suggestion to make the early game easier for newbies, while not changing the game itself at all.
One of the features of ADOM that most of us like is that races and classes are deliberately not balanced, instead, some are more challenging than others. But new players have no way of knowing that, e.g., a drakeling wizard is easier than a human ranger. They can have some slight ideas (farmers look difficult, etc.) but it would be good to tell them directly.
In DCSS (or at least in some version of it), the system to do this was that when you chose your R/C combo; easy, medium and hard combos were highlighted in different colors.
Apart from that, it also had two or three specific suggestions for new players: an easy melee class, an easy caster class, and... I don't remember, maybe an easy archery class or something like that.
I think implementing one of those two things, or maybe both at the same time, would make it easier for beginners to start playing ADOM without really changing the game balance at all.