Bigougit,
The biowheel isn't doing any harm (well, maybe a little if you take Alshain's POV), and the rest of the Emperor 400 is a good filter, traditional HOB, so no need to buy a new filter.
I think I understand your POV on the $1.85 tetras, etc. I got my first 5 gallon aquarium when I was back in maybe preschool, more than 25 years ago, and my first fish were tetras, barbs, etc. When I got a bigger tank later in elementary and jr high school, I eschewed the tetras as "little kid fish", and got into brackish fish, and also African cichlids. When I finally had the money and space for a 55 after college, there was no way I was going to squander the chance to finally have an aquarium big enough for big fish, and that's how it is now, big African cichlids. However, I can see someone also using a big aquarium as an opportunity to have a lot of fish of various sizes living together, to get to see big schooling behavior in tetras, and I have seen beautiful dutch concept heavily planted aquariums where the plants are the focus, but a school of neons, or congo tetra really add to the aquarium.
I have also found in my garden pond that my school of Buenos Aires tetras make great dither fish for the south american cichlids, reducing their shyness and making them more visible and active in the pond. The BA tetra also add interest in their own right, since all my cichlids are just a minor variation on the cichlid shape, and have slow, fluid movements, the more torpedo-like shape of the tetras and their fast, darting movements add variety.
Part of the reason that some of us "experienced" aquarists may eschew the starter community fishes is that they are so common, seen everywhere. I wouldn't be surprised if many of our brethren in the salt section eschew percula clowns, blue tangs, yellow tangs, and royal grammas, especially since Finding Nemo came out. I have to chuckle about the fact that practically every time I am in a fish store that also carries salt, I hear some little girl shout "Dory!" or "Nemo!". No one likes to have something that is common, that has become a cliche. But we have to be careful with this attitude. Even African cichlids have become pretty common now, and nonaquarists even recognize them. I see yellow labidochromis everywhere, even at Walmart.