If the dwarfs are red, they are males.
What worries me is the combination of fish in there - silver sharks are highly active, nervous, large-growing fish (to 14") and require a minnimum of 125 gallons. As they are schoolers, a group of 3 is advised as a minnimum. Clown loaches, simialrly, grow large (though, granted, a lot mroe slowly) and should be in a 90 gallon minnimum eventualy. The silver sharks are likely to stress the dwarf gouramies do to their high activity levels. The platies would be at risk if the sharks were adults as they'd make quick snacks (but your sharks are still young so its not an issue). The gold gourami, as I've already said, could turn out to be extremely aggressive - particularly if male - towards the dwarfs.
As things stand, assuming you have a large enough to accomodate the fish you own, they should all be ok together for the time being (until those sharks are larger and cause serious stress for your dwarf) - except for the gold gourami issue.
I would not add any more gouramies. They'll be fine on their own.
If your tank's not larger than 55 gallons, don't add any more fish at all and consider re-homing the sharks if it's smaller than 125 gallons.