Some people might have luck with the cherry shrimp and pearl gourami. The opaline gourami will probably eat them because they do get quite large. But it depends on the gourami, if you keep it well fed, you may not have problems.
If you want baby shrimp, maybe consider a focal fish with a smaller mouth to be safe. Maybe a couple of Bosemani Rainbows, for color?
If you get two mollies, I recommend 2 females, that way you won’t have a fry explosion. If you want fry 2 females and one male is recommended, but again a gourami may eat the dry.
Add lots of hiding places for the smaller fish.
I would recommend adding a snail or two, as long as they are different species, they shouldn’t breed. Like a mystery snail and a nerite snail.
Wait a couple of weeks between adding fish. If you go with the gourami, add it last.
It’s also okay to overdo the filtration.
I have an overstocked Barb community 29 gallon with a 75 gallon HOB and a ziss filter, this helps with keeping the beneficial bacteria numbers up.