the dwarf pleco wont get to big for the tank?
most do...plus I have never heard of a 'dwarf pleco'
ottos
cardinal tetras
ghost shrimp
panda/dwarf/pygmy cories
A divided betta tank
all these are things you can do with a ten gal,plus many more.
dont put barbs,they will pick at your betta until he's dead or has barely any fins.
there are dwarf plecos, bristlenose plecos only get 4'' and don't need much swimming room, also, i wouldn't keep cardinal tetras unless you are a very experienced aquarium keeper considering they are one the most delicate fish one can keep
good luck