Evolving Rules for my ACW Campaign

I've been working a good bit on the house rules for a planned ACW campaign that will feature 1/600 scale ironclads and 6mm figures.  I'm hoping to be able to field over 2,000 figures (remember their 6mm!) and a fleet of 8 Union ironclads / warships pitted against 6 Confederate vessels.  I'm about 75% complete with the painting, so the campaign rules have been an area of focus over the last few days.

The game will feature combined land and sea operations and is very loosely based on the Peninsular Campaign of 1862.  The Union player will need to capture 3 out 5 Confederate held forts.  The Confederate player can win by either preventing the Union from achieving it's objective or the CSS can achieve an immediate win if it captures 1 of the 2 union forts.  A very rough campaign map is shown at the bottom of this post.

The campaign will be played with a double blind system for strategic movement.  I've been playing with trying to web-enable the campaign movements to speed things up.  All battles will be fought on the tabletop with the miniatures.  Land Battles will be fought using Black Powder and I'm still looking for some naval rules - most likely the Featherstone ones that were brought to my attention by Steve-the-Wargamer.

Any feedback / suggestions would be greatly appreciated.

Forces:
Union
3 Infantry Divisions (12 Infantry Regiments each)
2 Calvary Brigades (2 Regiments each)
20 Artillery Batteries
8 Ironclads
6 Transports (can carry 1 regiment or 2 batteries each)

Confederate
2 Infantry Divisions (12 Infantry Regiments, each)
2 Calvary Brigades (2 Regiments each)
14 Artillery Batteries
6 ironclads
4 Transports

Campaign Rules:

Movement (in Squares):
Rail              8  (Note the confederate player can use
                         off-map rail movement,
                         it takes 4 turns to get from
                         point A to point B via rail)
Naval           6
Road
  Inf / Art      2
  Cavalry      4
Land
  Inf / Art      1
  Calvary      2

River Crossings:
Major Rivers can be crossed only at a ferry.  A ferry is useable if no enemy naval units are within 3 squares

Passable Rivers may be crossed using normal movement rates

Forts:
Each Fort is assumed to have a static garrison.  Can be placed under siege by a force equal to or greater than 4 infantry regiments.  After the 4th turn of a siege, roll a D6.  The Fort falls on a roll of "1".  Subtract 1 from the roll for each battery of artillery present at the siege, up to a max of -2.

Forts can bombard adjacent enemy fleets, rules TBA.

Campaign Map Line of Sight:
Infantry: 1 Square
Calvary: 2 Squares

Deployment:
Union
2 Divisions, 1 Calvary Brigade on the east bank of northern most Confederate Fort
1 Divisions, 1 Calvary Brigade, Entire Fleet in Upper left right Union fort

Confederate
1 Division, 1 Calvary Brigade in near Upper left fort
1 Division, 1 Calvary Brigade in Southern portion of the map
The confederate fleet is based at the two indicated points, with at least 1 ship in each area.