I love it when a plan comes together!
1) Can a player decide to eliminate a reinforcement that he cannot place once he draws the unit?
(I'm thinking of Jacquinot's 1 point cavalry units if the Prussians overrun the entrance region.)
2) Can Prussian tactical leaders support battles involving "British" units and vice-versa?
Very interesting questions Dan.
The answer is negative for both.
Do you believe this something not clear enough in the rules manual?
ALL THE BEST