Hi. This is a wonderful game; I came to it yesterday from gamebanshee and I'm loving it. I'm 36, from the States. I'm trying the 2 cleric, 2 wizard strategy (before reading that it was the second recommended party in the faq). I can tell that the game will be quite challenging, which is very refreshing.
I highly recommend this to anybody who is wondering. I agree with you down the line about your design notes philosophy, by the way, except for perhaps preferring to have one character to several, although your point about the character then needing to be a jack of all trades is quite valid. I'm finding that I enjoy the party-based nature of this game quite well, despite my mild preference for solo chars.
I'm running into a few bugs, so I'm hoping that a quick and simple patch can come soon. After beating the water elems and orcs, my wizards leveled as knights regarding hps and not getting new spells, although they do correctly show up, and presumably act, as 2nd lvl wizards now. I believe that I also ran into a bit of weirdness with sharing spells not working perfectly. Also, when you scroll through your chars in the char info screens, the stats for the weapon and AC and such tend to lag one char behind, so it you scroll from your morningstar wielding cleric with 17 ac to your dagger wielding wiz with 18 ac, it will correctly say that you are looking at your wiz, but it will list him as wielding a morningstar (with to hit and dam for the cleric still as well) with the 17 cleric ac.