If you're already feeding a decent quality pellet, bloodworms aren't going to add much in the way of color. The red in bloodworms comes from an iron containing protein, not from the carotenoids which are actually the natural color enhancers in shrimp, krill, salmon, etc. And, actually, I've done a lot of food testing and I found the biggest difference in color came from the staple pellet/flake I selected. After they already have good color, based on good health, good nutrition, and clean water, whatever treats I'd add didn't make any discernible difference color-wise.
What I've found looking into the nutritional aspect of bloodworms, is they're not particularly solid nutrition-wise and are more like candy for fish. Especially frozen, which are @ 90% water-- compare guaranteed analysis on labels between frozen and freeze dried, frozen is actually very low in protein and nutrients, freeze dried fairly high in protein, though bloodworm protein has an incomplete amino acid profile, anyway, according to the sources I've read. Vitamins are often added to frozen, but a lot of good it does when most of that melts away with the water. That said, I've sometimes fed freeze dried blood worms as a treat to my geo and angelfish tank and it seems to encourage especially the wild angelfish to spawn a little more often-- adds absolutely nothing to their color, though.
I expect you're getting some of the comments about your tank stock because there are fish there that can vary from aggressive to pugnacious to the occasional complete psycho, depends on the tank and the individual fish. That doesn't mean what you have can't work, and you may have put together a balance that will be fine, but if you're looking for experienced opinions, a reasonable take-away from it is just to be aware you may need to make adjustments at some point if one or more of them decides to go off like they're capable of doing. Aggression is often relative and can vary within the same species for a variety of reasons, but it can also be unpredictable as fish get older.
As far as water requirements for the fish I see, shouldn't be a problem. Any of those fish either come from varying enough habitat or are adaptable enough to do fine in moderate ph and hardness. Personally, I've successfully kept a fairly wide range of both rift lake and new world fish in pH in the mid 7s and moderate hardness.
