Econ, your trying to control to many factors. Let the players politic it out in the council if someone is unit hording - they can do it outside of wartime as well, the civil war mechanic does not actually enable people anymore then it would outside of it. If you look previously at LotR, the Order and the Asteri both horded units like mad outside of civil war.

Second, disabling unit prioritization may be bad in minor skirmishes, but it is good in the sense of forcing people to act. A compromise would be to reduce the number of prioritization to 1 for all neutral players. This will allow unit recruitment outside of the civil war to continue, at the kingdoms detriment, and also gets those not involved to try and broker peace between the two nations hating each other. Couple that with the dueling mechanic, and the stigma that will likely go along with grinding the kingdom to a halt over a minor border skirmish, and this won't be abused at all.

I have nothing against adding money to the bank so long as it is returned to it's previous level, but that may be a bit of a hassle for the GM.

And as far as Bankrupting the country - you really think the other players will allow that? This is another thing that should be fought IC. If the Seneschal is trying to drive the kingdoms economy into the ground, then we as players, who oppose this, need to do something about it, not let rules support us.