Breakfast is the most important meal of the day (says she who never used to eat it). You have been fasting since you went to bed and you are now breaking the fast hence the name.
It has been proven that those who miss breakfast will eat more calories during the day. If you have occasions when you know you are going out and will eat over your calories then it is fine to swap things around. Please don’t make a habit of it though.
As far as calories and fat content goes it is the overall day that is important so yes cut down on one meal and add on another.
Did you also know (now don’t all go mad on this one either) that weekly calories/fat is important. If today you ate out and find you are 200 calories over your limit, panic not because as long as you correct it within 36 hours it balances out, so tomorrow you can cut down and there you are a perfect week.
This does not give you an excuse to binge though, but it might help the thinking, I blew it why keep on with it.