i was concerened on the size of all the files if i put them in mymission folder, and writing the description for them would be crazy
I would think the size would be the same as the equivalent video file, since you are just separating the pictures that make up the video.
The description would be easy to do. All you need is one picture box, then use the ctrlsettext command to change the picture path. If you named the pictures 1.jpg, 2.jpg, 3.jpg, etc, then you could just have a small looping script that would run thru each of the frames. I haven't seen the Tomahawk pack, but I would assume they did something similar to this.
This could not be done with cutrscs though, since those take a second to fade into view.