So, it works pretty well, but want to make a few suggestions, which should take a grand total of 3 minutes to fix:
1) Can the entirety of the contents of LivePress.php be put inside an if(is_admin()) tag? There's no need to be calling the CSS and functions on the posts/site. Well, unless it pulls the comments from LJ or something, which I don't think it does. If it does, can we make a setting for it?
2) The following files need the stylesheet link changed:
LivePress.php, lpextras.php, lpmoods.php, lpmusic.php
The line should look like this:
echo '<link rel="stylesheet" href="'.plugins_url().'/live-plus-press/LivePress/LivePress.css" type="text/css" />';
Depending on what page you were on, it was trying to call a .css file that didn't exist
And now that I think about it, 3) It doesn't want to retain the linkback and disable remote comments checkbox in the settings, and if I checked it on the individual post, it doesn't stay.
I'll take a look at it myself when I get some time, and would eb happy to help, but I thought since you're much more familiar with the code, I'd bring it up with you.