Hi! I'm not to sure if you can edit the user but you can open the old server of otaku streamers i edit my profile picture there and it also transfers here in the beta server you can try it. :) hope this help you.

I haven't found where you can change your username here on the beta, but I believe you can change your user 1 time on the old version.

Here on the beta you can change your avatar by going to your profile, and there should be three little dots in the top left of your profile cover. It seems a little buggy at the moment tho, sometimes I can see mine and others I get an error. 

I really hope they are able to update the profile and things on the beta site soon! I miss the environment of the old site, but I do appreciate this more updated beta version.

are you having any issue with uploading a profile image by chance? it keeps like deleting my image for some reason...

I kept having that problem too..... but it randomly fixed itself eventually.