+2 for foot holding fire, consider reducing to +1. In all cases this fire is going to be sporadic at best. Charging formed foot frontally should be a dicey gamble for horse, but once they make contact the advantage should be theirs.
The original turn sequence flow works fine, rout moves etc at turn start.
How many times is a unit allowed to rally from rout? Suggest raw/drilled once, elite/guard twice. Failure = remove unit from play.
Retreat, face enemy? Rout obviously should not.
New movement rates seem to be ok, have not played with this version of rules yet.
Changing a Defend order makes no sense, unless your intention was for it to take 2 turns. As written the CinC or Brigadier joins the unit, if they had defend last turn and you 'decide' to give them another order it must be defend again. But if you want to change their order to Move you give them no order the first turn and then you can issue the Move order the second turn. All based on your Order Allowance for the turns of course. Was this your thought process? If so, average brigade 4 units, if all 4 with Defend then potentially 8 turns to change all units orders to Move after the General Order was changed by CinC for the brigade.
Also the brigades 'General Order' given at game start and an Order Allowance order given turn to turn should be clearly defined.