Well, with the margarine on toast, etc. I wouldn't worry too much about the difference in calories. For the amount of margarine most folks use to butter their bread, you're not really getting a lot more calorie-wise, and the benefits to your heart would seem to outweigh even that.
As far as baking, I rarely use any fat...the subs I use for eggs (applesauce, bananas, tofu, egg replacer, etc..) generally keep things moist enough.
The ones I pity are the ones who never stick out their neck for something they believe, never know the taste of moral struggle, and never have the thrill of victory. - Jonathan Kozol