Wow, there is a lot going on there.
Just looking at your code, you’ve got styles being assigned in your HTML, your CSS, and your JS, for example. It’s hard to keep track of. In general, styles should be addressed in the CSS, given to classes. In HTML you can assign the classes, and in the JS, you can change the classes if needed.
I would suggest simplifying. For one thing, for me, the “make everything pretty” is the last thing I do. I like to make sure I get the JS to work since that’s the hardest part. If I worry too much about styling in the beginning, it just gets in the way. To me the styling is the easiest part. And it’s hard for me to see how I’ll want to style it until I know what I’ve got.
My recommendation would be to get rid of all that styling and just make a simple list of the data in the screen. Make sure your logic is working. Then build from there.
For example, instead of writing out each JSON call individually, what about a loop? Put your usernames in an array and loop through that array, with two JSON calls in the array, one for users and one for streams. Just output that to an unordered list. Then build from there. Take it one step at a time and test as you go.
Sorry I don’t have time right now to go through your code, but my advice probably would have been the same anyway.