There are more experienced members here who can be more precise with answers to your question. However, here is my attempt to help
The 600 calories for males is a rough guide. The figure should ideally be 1/4 of your TDEE. As for exceeding the 600 and its effects, it depends on your TDEE. If you were more active, exceeding the 600 calories would probably not make much difference. If more sedentary it might.
To a large extent, if it is a one off, don't stress and make it up later. If it is constant, it may be an issue. But by and large, you are still restricting your calories and you should still see weight loss.
The timing of the meals is up to you as long as you stick to the caloric restriction. For myself, I save all the 600 calories for one meal over a 36 hour period as I find it easier. Do whatever works best for your circumstances