I have developped this plugin for small gamer team / gamer team usage, not for mass sharing (take care of that idea in your spirit If you do not want to be disappointed) => #4 isn't an issue, it is voluntarily (because small team usage/gamers team usage).
If you desire to makes small change (to not displaying the thumbnails list under one live stream) view http://wordpress.org/support/topic/plugin-livetv-bundle-streams-per-page?replies=14
#1 This alert comes from own3d/twith. If a user is connected (via original site) and comes on your site, it will be automatically connected to the original chat box on your site but If a user is not connected to the original site own3d/twitch, the inputs for pass and for name are viewable without "enlarge" but if you need to enlarge, it's in /frontend/frontend...php
#3 If you choose "members only" a new box appears in your administration named "Define global message and login url for visitors". Don't leave empty this part.