Funny - for some reason, I specifically *dislike* ADoM :)
Trog (one of if not the easiest god to please: killing things while praying is all you really need to do [though I sacrifice poisonous corpses on occasion as well], and not casting magic from memory is all you need to *not* do [why in the world would you make a troll magician in the first place??])
Makhleb and Vehumet are in every way easier - only forgetting them angers them, they're glad to accept the killing of demons and the undead in their names (while Trog doesn't care), and summoned allies please them when they kill, whether you're praying or not. Considering one grants you the divine power of demonic summoning and the other's a god of magic conjurations and summonings (so you'll be getting the books as gifts, sooner or later), there's a good chance that all you'll be doing is invoking/casting, and then sitting back to enjoy the show. You end up playing a horde's sole commander, rather than a lone warrior :)
Also, using the most powerful summoning spells and abilities in Pandemonium gives some really sweet effects ;)
As for Troll wizards, if you check the spoilers you'll see that they're better at Earth Magic than they are at most forms of armed combat (too bad they suck terribly at Spellcasting). They're also not too bad at Necromancy.
Now, here's something I've been considering: a Troll Warrior of Kikubaaqudgha.
By investing most ability gains in Intelligence, and by using a decent ring of Int or the like (cap/wizard's hat of int if you're lucky, randart if you're patient), you'll certainly have a score of at least 12, and pretty fast. That's more than usable, considering Trolls are good at not wearing armor or shields and at not wielding weapons, and Kikubaaqudgha grants protection from Necromancy miscasts at high enough piety so there's plenty of room for magic practice.
Kiku (it's gonna' smite me for that, isn't it? :P ) also gives Necromancy-path books, so it's only a matter of time before you have access to them, and therefore there's no question of luck.
MPs're a problem, as Trolls have very slow natural access to it, but since they're massively strong regardless of playing style, they'll have plenty of room for chunks for castings of Sublimation of Blood. Since they're great unarmed combatants, this will take less time than it would have otherwise.
They don't need to cast Regeneration at all, and Pain hardly has a side-effect on them.
Now, if natural regeneration's kept under the influence of Necromutation, then with some planning they'll hardly need to eat ever again, while gaining immunity to several nasty forms of damage and still recovering lightning-fast, as Trolls do. If it isn't kept, then meh, they'll regain HPs like everyone else :P What's certain is that this will counteract many of the hunger issues, including those resulting from being a low-int-wiz. That's likely to be very unbalanced, as hunger's the Troll's main weakness, once Dragon Armour's found/created :P
Reaper summoning, Death's Door protection, eslavement of the undead, recall and racial access to massive melee skills are all gravy. Hell, he'll even be able to cast Bone Spray (that was the name, right?) often, as he'll have the strength to carry skeletons around!
The only serious problem with this character is that AFAIK Kiku <<TFoN is struck by a bolt of draining>> doesn't accept demon kills in any way, making the most readily available type of monster during the late-game useless piety-wise. This also means Pandemonium's a dangerous place to go for fear of excomunication, as you'll unavoidably "forget" your god of death - and I just can't play a game where I can't storm Pandemonium :)
Another minor issue is that this plan is very much a vision, meaning that it's based on how the character will turn out after some very rigorous play. Most of the time, you'll have to deal with hunger while still practicing your magic skills, all while finding living victims frantically. Good thing you don't have the option to sacrifice corpses, as that would put you in danger of your [very hungry] self ;P