Okay, here are my thoughts/comments/random typings so far:
Bront: I liked Zan in Warriors of the Coast, and he might fit here. Of course, you'll have to be free enough to play. I am also wiling to entertain other concepts.
Enforcer: I have not seen the Combat Focus feats in play yet, but my overview did not give my too much to pause over. Only question I would have is what would break the focus---I'd probably rule a spell effect like
calm emotions or similar would. I like the background.
kinem: Not enough info to comment on at this time.
Eva of Sirrion: The Sun and Sword Military Magic Academy is an interesting idea, but probably associated with one country more than being an independent agency. The
Player's Guide to Eberron posits that such an academy may have been in Cyre. As a member of a House, however, Myran could have easily bought herself in any case. Gives you an opportunity to have known any of the Cyran characters. In addition, adds a little something to the RP possibilities to know that your academy is no more, having been destroyed.
As for your particular implementation of the concept: I assume you are going warmage to be more of a *blow things up* fighter/mage than a *augment myself* fighter/mage. I have nothing particularly against the class. Warmage/cleric is going to give you a case of MAD and not not allow you to Mystic Theurge until you reach more than the game's halfway point (8th level), but warmage/favored soul is not going to get you into Mystic Theurge until near the end of the campaign (9th) if you make that far. Thus, you may wish to take that into account.
ByteRynn I like the background, and the Vol dupage is good stuff. I have a little trepidation about the knight class, mostly about some of its challenge abilities. I'm not going to squash it, but be aware that I'll be wary of abuses.
GwydapLlew The sketch of the concept looks good, and the possible integration with DEFCON's character is fine. I will give you both plenty of opportunity to 'fall off the path.'

But both of you will have to take care of playing well with others (mostly the PCs).
DEFCON As I said for GwydapLlew, I like the concept an the possible integration. Also s I said above, play well with others. I'm not looking for lone wolfs; they can be frustrating in RL and really annoying in PBP.
penance I'll be upfront and say that psionics will not play a role in this game unless there is a psionic PC, so a lot of your character's motivation/uniqueness is not applicable. In addition, spellsword is a very week PrC (though an interesting concept); I'd suggest something more along the duskblade in the PHBII than the fighter/sorc/spellsword combo. Finally, with the build you are describing, you will only get to spellsword at the very end (9th level).
Drowned Hero I like half-orcs, and I like half-orc druids. I can see how you are trying to tie a hatred of undead into your background. The only comment I have right now is that druids to not make great ranged combatants, being limited to spears and slings.
That's all I got for now. Any questions? Let me know!