Yes, you can take the film pack out in the light. It has opaque paper sheet in front of the first frame. Full instructions are probably on the data sheet in the Kodak box, assuming it's still sealed.

If you've used Polaroid pack films, the concept is similar, except that you don't pull the exposed sheet out, the tab pulls it around the side of the pack and behind the unexposed sheets.

The film is the same thickness as roll film, and it's also slightly smaller than standard sheet film, the guides in the FR tank may be big enough to hold it, but it may not work with the mod 54. However, as stated, the FR tank has never had a very good reputation, so tray development may be the best.
Getting stuck in the dark with 16 sheets of loose film may not be an ideal time to find out they won't work in the FR tank Your bonsai may like it though.

It is possible to open the pack and remove the exposed frames, then put it back together and back into the holder, but you are probably better off using all the frames before processing.

I've got a few film packs to use one of these days, if I can just remember where my film pack adaptors are.