My cats routinely 'throw up' pretty much just water in the mornings. They do it when they're trying to get rid of a hairball, so some weeks it's every morning, and other times it just randomly throughout the month. And I'm always thankful it is before breakfast and not after, because I get really irritated when they throw up all their food.
As for feeding times...I'm the oddball around here and only feed twice a day. We fed dry food twice a day, so that's where we started with the wet food. Both cats adjusted just fine to it, tho sometimes we catch Truman trying to clean up the leftovers from the dog's dish because he's hungry. And Max went into remission on this feeding plan, but I know that many struggle with this. If we had had problems with his sugar control, I would have bought an auto-feeder and given more smaller meals throughout the day.
I feed both cats together, from the same bowl...sometimes Max is over-dominant and eats more than his share, but I haven't noticed Truman losing any weight, so all is good in the end. And they don't fight over their food, so this is just laziness on my part--they tolerate it, and I don't have to wash twice the dishes, so I haven't changed it.
We feed 1-5.5oz can plus 1/4 of a 5.5oz can of Friskies each morning and again each evening. This feeds my 14.5lb cat and a 12lb cat just fine. I think it basically works out to about HALF of the recommended dosing from the cat food company. Actually, I probably should feed separately and reduce Max's food because he is a bit overweight, but again...laziness on my part. ;-)