The food and water one would be fine as a unit ability but they only can cut off water and supply routes. It can't force the men not to forage or find alternate methods of sustenance.

The disloyalty one is a bit strong since you're knocking out 1/5th of the enemy army for arguably half the encounter. I'd say 1,000 units are disabled for two posts at the start of battle.

The interrupt communications was somewhat of an autohit which I had to correct in Shin's army. So I'd be okay with you intercepting and learning enemy intel, but not manipulating their intel. Perhaps you could add a clause where you can suggest a piece of intel per post in an OOC tag and your opponent can choose what to do with said intel? It'd have to be one or the other though since they'd be separate abilities. Essentially stealing intel or planting intel.