Hey there @irastra.

1. I think it's a great idea to put all of the curation groups in one place. Certainly that's an initiative that you might consider doing yourself!

2. I also had the issue of applying for Streemian with a typo in my email address. There's nothing you can do. Their support leaves much to be desired and has not responded to my query. Therefore, if you want to be able to trail other accounts, you have a couple of options. (a) Sign up at SteemAuto, a similar service created by witness @mahdiyari. It can offer similar functions as Streemian. (b) Set up your own curation trailing bots on a local machine! This is the solution I used for my account. I decided to use some bots created by @inertia, and I did a tutorial post series about how to set one up!. I hope that someday Streemian will fix the issue with their sign up process, but until then, I wish you the best in finding an alternative.

3. As far as I know, your username cannot be changed once you've registered it.

I hope this helps! Let me know if you have further questions!