First 3 pics is definitely a croton, maybe croton Petra. They like lots of sun and kept just moist. They do best in direct sun but you can get away with filtered light although the leaves won't be as spectacularly coloured. It looks like at its old home it was light deprived that's why it's so leggy.

The fourth pic I can't really help you out with. It looks like it was a bonsai at some point. If anyone is into bonsais they will be able to give you more info.

It is a croton. I would cut it back halfway and make cuttings of what you cut off. Your schefflera would do alot better if you planted it in a pot with soil.

I'm curious about the 2nd one, maybe it's Schefflera brevipedunculata or Pachira. Doesn't look like the 'regular' 2 kinds of Scheff people usually have. The way it's in/on that rock reminds me of this plant.