As for the lists: perhaps not make both a cavalry AND an infantry unit obligatory. That way the army is just too "set", meaning you can't make a more specific army theme within the faction theme.
For example, when first planning an army, I would have liked an entirely Sigmarite force, sent out by the Church to aid but act independantly from the rest of the Stirland army. That would have meant Knights and Flagellants, but no state troops. It would have been a true Stirland list (as true as a Kislevite army is to the Middenlanders, for example), but with a little twist.
However with the army list as it was presented, those plans had to be changed. Taking a unit of halberdiers (and with how great halberdiers are, I knew I needed lots, with large detachments, to not let them be a complete waste of points) would just not have been in style.
The same would be true for anybody wanting a White Wolf themed army, with little infantry, or an actual Stirland list, unaided by the Sigmarite church. The Middenlanders had more freedom in this, since they could also take Kislevite lists (though not the greatest lists around, it's something completely different).
My advise: less obligatory units. Perhaps make it obligatory to take at least one unit of cavalry OR one unit of infantry, but not both.
Further, I appreciate the creation of so many new units, and the addition of that many DoW units as cores, but I think Middenland has been a little left out.
Lastly, I find it strange that Dwarfs are allied with Middenlanders. Weren't they best allies with Sigmar? Why would they turn against His followers, then?
Further, I don't think there's anything over- or underpowered in the list, it's been quite equal.
I wouldn't know about the characters, never used them...