I'm only going to comment on a couple things here...really.
First, absolutely forget livebearers if you have soft water. They must have mineral in the water. Clamped fins, shimmy, and various skin disorders are very frequent when maintained in soft acidic water. Hardness must be medium and pH above 7. Keeping them in acidic water is frankly cruel to the fish.
Dwarf Gourami. Not a recommended fish. Interestingly in this month's (December) TFH there is an article entitled Community Fish Caution, written by Howard Goldstein, and the DG is included. He sums it up with "I recommend avoiding the dwarf gourami altogether." So do I.
Last for now, I would increase the loach and diamond tetra if either are selected. Five or six Botia kubotai are best, I've had 5 (had six, one died, this does happen
) for over 2 years now, they need company. Same for diamonds; a group of 7-9 would be best, and be sure to get a good proportional mix of male/female, say 3m/4f or 4m/4-5f. It's been a while (14 years) since I had these; they spawn regularly and are extremely beautiful.