Hmm.. two handed? I always stick to one-handed. It was proven that one-handed are by far more effective in the game. Lots of pluses outnumber those of two-handers, hands down. Plus, it's generally easier to raise onehander skill, and requires less strength. The only real significant pro that twohanders have is the range, however I haven't really had any problems keeping orcs or raptors at range with a onehander either, if using side-strikes.
So if you're mage, stick with onehanders.
Mage is, indeed, quite hard to play in the beginning. Frankly, I never liked mages in Gothic. They kind of don't fit with my view of magic user in general, and I don't find them particularily fun to roleplay. Probably, because Im spoiled by DnD games where mages were much much better, by all means. There you really could specialize in magic only and become immensely powerful, here in gothic you have to walk the battle-mage path, which i don't like at all.
However, with NoTR mages are indeed immensely powerful all by themselves (even without summons) due to the uber spells (you'll see them later), but that's only in the end stages.
Don't get me wrong: it's tnot tht I don't like the challenge of the mage, I just don't like that there is not much potential in spells, and they are so totally limited in terms of diversity: basically, just attack spells and summons. No invisibility, no levitation etc. Mages kinda feel.... truncated, abridged, catrated if you will. Ideal for those who love playing battle-mages, no doubt.