I'm not an expert, but adding a window into a wall will not make you need footings under the point loads. That's more for when you tear out the entire wall and add a great deal of weight at the ends of a large beam. I think you should be fine.
You will be fine---I usually add a 2x10 or 2x12 double as a header--that is over kill for a small opening---but it is what I do--saves time--easier to keep the wall flush and it is plenty strong.I'm not an expert, but adding a window into a wall will not make you need footings under the point loads. That's more for when you tear out the entire wall and add a great deal of weight at the ends of a large beam. I think you should be fine.