Attacking an ally is just completely unrealistic, unless you don't want that person to be an ally anymore.

Imagine any war where one ally turned on another. Do you think that the excuse, "oh, sorry, but I needed the resources of your territory and I wasn't in a position to attack an enemy of ours ...

The answer to this is no card for if you defeat an ally.

Convertability is good.

In fact, I would just award the continental bonus to the player that has the majority of territorities and/or troops in the continent (as in Risk II). That way there is no need to attack an ally or convert troops.

Yes, please add this little thing. I did it again. 3rd time in 5 games. My fault? Of course. That's why I need help.

Could you add a Confirmation box so that when people (me) accidentally click the "end attack" button before having done anything, well, we have an out. Losing a turn due to mouse slippage isn't too fun.

Excellent.