It sounds like that species likes warmer water (mid to high 70s) which is incompatible with the white cloud minnows (who like temps in the high 60s to low 70s). It looks like it sometimes also eats fish, so not sure that's going to work out in general, but I don't have any firsthand experience. If you got any fish I'd make sure they're larger than your turtle's mouth (or than it will be at adult size). I'd also be a little worried about the turtle ripping out the plants, especially on the platform but to a lesser degree, the underwater ones, if you don't let them root fully before adding it in, but if it's just a baby now that might not be an issue.
HC especially needs high light and CO2 to grow well. If you're putting plants under the platform, I'm not sure how you expect them to get any light... Maybe I misunderstood. I'm also not sure that the turtle alone, especially if it's a baby, is going to provide anywhere near enough fertilization for the plants you want to thrive. I'd also look into finding out the PAR rating of your lights to make sure it's not going to be way too much; you could end up with algae problems.
HC especially needs high light and CO2 to grow well. If you're putting plants under the platform, I'm not sure how you expect them to get any light... Maybe I misunderstood. I'm also not sure that the turtle alone, especially if it's a baby, is going to provide anywhere near enough fertilization for the plants you want to thrive. I'd also look into finding out the PAR rating of your lights to make sure it's not going to be way too much; you could end up with algae problems.