Most likely this will be very impractical, but I wont say that it is impossible I will just make specific comments to your questions.
PCMCIA is absolutely necessary, without it the main uses for these things is out the window. Without wired/wireless connectivity it is very limited.
CF, same as above. CF and PCMCIA use the same interface for the most part, except that CF uses fewer connections and thus limits it addressable memory space.
Touch screen needs a controller. It is an analog device that requires some slightly complicated hardware to determine the X,Y coordinate. Burr-Brown made a chip that would do this but has since been bought out by TI. The specs are here: