You've got a bit of a mix going on there,
None of the fish you've got should really bother the synos though could I suggest you get the comet moved as it shouldn't really be kept in with tropical fish and will also grow quite large.
The other fish will also be at risk as the decorus grow, as the will eat smaller fish.
What size tank are you keeping them in and with what filtration?
Could I suggest you go back to the shop you bought them from to confirm what they are.