Gone U/S...
On layovers we always get 'per diems' which is the food allowance given to us by the company via the hotel. The amount varies depending on the length of stay and the standard of living/the hotel of the destination.
Flying hours vary per month, personally I have done between 50-90 per month. It will vary on the type of flights you get, and will decrease if you have leave or ground school for that month.
You can't really set your min/max flying hours with the company... I guess you can bid for a certain number of flying hours in the bidding system, but once the rosters are released you take things flight-by-flight. The flights with the highest amount of hours tend to be JFK and the Australian flights, and these are quite difficult to swap into.
I do know that if you're on a day off you can register your interest as being free on that day for flying, however they have to go through all the crew on standby first, and check that you're legal to operate.
Hope that helps