If you're starting as an OgWz, I think you should put a stronger emphasis on conjure flame's success rate, along with summon imp and mephitic cloud. Those spells are strong enough to kill most threats if used properly. Summon imp is good because crimson imps are difficult to hit, so you can use them in tight corridors to create some room to create a conjured flame barrier, along with the imps acting as a wall so enemy monsters aren't going to be hitting you with whatever nasty branded weapon or wand (e.g. polymorph) they might have on hand as they burn up within the flames. Strong monsters who are still too cowardly to step into a conjured flame can be pincered between two conjured flame clouds and then you can hit them with mephitic cloud to make them stumble to their fiery deaths.
Since skill dancing is no longer necessary, you don't really have to use a mace or flail weapon unless you happen to find one with a useful brand, or one of the rare ones that are good like the evening star or demon whip. Basically, you should get your magic skills to 1% failure, and then work on maces and flails up to 16 for the GSC unless you happen to find a spellbook with something more useful to increase your survivability than a plain old melee weapon.
My rule of thumb when using generic weapon is just focus on using the one with the highest attack power that's closest to its minimum delay. See here:
http://crawl.develz.org/info/inline.php?q=attack_delay