Then the app would simply be terminated in another way.

To use as trickle I think that Goats have the best ROI as they cost 35 and trickle 1 food per second. That represent the 2,85% of the investment while cows give 3 food but cost 150 food, which is only 2% of the total cost of the cow. Also they train faster so they start "trickling" before the cow so the total benefit should be a bit more.

Wonders are one of the most useless building in the game. They super expensive in resources and time. I don't know if I've seen a game all alpha where building a wonder helped that team (assuming it isn't a win condition). 

This is a real hack. I like it.  My main point is that food is the slowest gathered resource. So you can't value it the same as the others in a 1:1 basis. It's also the resource most likely to hit 0 when a player loses. Additionally, the auto train cows part can get a player into real trouble if their food supply suddenly runs low. 

Speaking of which, why don't we just disable the ability to exit a game without resigning? Just turn the button off until the player has resigned.