I am playing an adventurer. All of those are weird to begin with. BUT I am playing it as a alchemist/mindslayer.
If you are actually curious this is my current set up
Cunning / Shadow magic 1-1-5-5
Spell / Wildfire 1-1-1-5
Spell / Temporal 1-1-1-5
Spell / Explosive admixtures 5-1-5-0
Cursed / Gloom 1-1-1-5
Psionic / Projection 1-1-2-0
Psionic / Psi-fighting 1-1-1-0
bone shield 1-1-1-1
Technique / Combat training 5-2-2
Spell / Stone alchemy 5-5-1-3
Spell / Staff combat 2-5-0-0
Wild gift / Call of the wild 1-1-1-0
Wild Gift / Harmony 1-3-0-0
Psionic / Finer-energy 1-5-1-1
So my main forms of attack are channel staff, alchemist bombs, and shadowstep. Alchemist bombs and shadowstep manage to hit me with stun a really large percentage of the time(the whole point of the weird wildfire/harmony build is to stack haste from hitting myself with my own bombs). It does not actually do the 500 extra points of damage to me but the 4 round stun on someone who stacks haste is a pita. Fixing that would fix it yes but is not as good as just making it a sustain with an instant on/off switch.
Note that since I have stone alchemy qualifying for ANY prodigy is close to trivial. Vestements of the conclave, a ruby-diamond voratun neck, and another randart stat hat means I can actually go above 60 on every stat at the same time if I really wanted to. Qualifying is rarely the problem. The hardest qualify was the first one to get crafty hands, had to use 38 points of dex equipment to get that one
With finer energy manipulation channel staff with a good staff is fairly impressive, especially after double bumping that element type from using the dual staves. My normal channel is around 600 damage, adding a 30% will modifier or 50% magic modifier would certainly not hurt.
I can see exactly the same problem with almost any build that hits itself with aoe damage (so archmage, alchemist, arcane blade, and shadowblade are right out). This begs the question of who exactly do you think this prodigy was made for?