The female headers included in the kit do not have the long pins. If you have “arduino female headers” with long pins, then you can certainly solder them on the outside set of pads. This kit was designed many years ago, and female headers with long pins were not available for a decent price.
Make sure you don’t solder the female headers that don’t have long pins to the outside pads, because then there are no male pins to plug into the Arduino!
Generally, this shield is not going to be stackable with anything else because it uses a lot of pins and functions of the Arduino. What shield do you think is stackable with the Video Experimenter? Most shields are not stackable from an electrical perspective.