Hello! Welcome to the forum. Here is my advice:
1. I'd only put one dwarf gourami in a 10, if any. Most people recommend keeping them in 20 gallon tanks at the least.
2. In a 10 gallon, your options are definitely limited. Some great options would be pygmy cories (hard to find but super cool) or ottos. You could definitely keep some shrimp (ghost shrimp or red cherry shrimp are both easy to keep) or some snails (nerite or mystery).
3. Given a large enough tank, there would be enough hiding spots and space to lessen aggression, but since your tank is only a 10 gallon, there would definitely be issues, which is why I only recommend getting one.
4. Just a warning- dwarf gouramis tend to die randomly for unknown reasons. Some say that it is a genetic issue (they have been bred in captivity a lot) but there is no certain cause. Also, dwarf gouramis are very susceptible to bloating and parasites. I have had 2 of mine (I no longer keep them) die from what seemed to be internal parasites (in this case worms), causing them to look bloated.
Hope this helps!