Is #1 possibly a Campylocentrum? Can't think of anything else it might be.
Agree that #2 and 3 is probably a Pleurothallis.
Wonder if Brachionidium is correct for #4 - doesn't Brachionidium have joined lower sepals? This doesn't seem to have that. It's not a Dracula and doesn't appear to be a Lepanthes. Have to do a bit more research on that one.