Okay, I've tried your code for #1 on a hidden skin. I'm putting it now atop our present forum skin, right below the banner and on the same row as "Site Focus", etc.
EDIT: Okay, I've copied it. Post more improvements and suggestions here, esp with how that "Let's chat!" pane looks. Make the font bigger and similar to the "Site Focus" etc links beside it.
Other limitations:
1. if we're aiming to get this live chat going as soon as possible, then we'd have to rely on PK staff on active duty. I'm one of them, and I can change forum layouts using HTML and perhaps a bit of CSS. Ie, if you guys give me the HTML and CSS codes, then I can copy them to our forum skins.
I don't know PHP, but if you can give me some codes that I could copy onto our HTML templates or CSS, then okay, let's try that.
2. None of us current active-duty admins (Adam, Bec aka Harry/Hermione 4eva, poppy, myself) have permissions to edit layouts or upload files in other PK sections:
-fanfiction.porkey.org,
-www.portkey.org portal,
-chat.portkey.org,
-gallery.portkey.org,
-recs.portkey.org
-users.portkey.org
For editing and uploading there, we'd have to rely on NAPPA or James. Last time they found time to change those sections' layouts, templates and coding was sometime before Book 7.
We don't begrudge them their busy real lives, but it'd be pointless to wait for them to have time for this. If they stumble on this thread, then of course they're welcome to make improvements. We have a long-pending request to NAPPA to update the links in those other PK pages.
3. For 6+ months now, we've asked NAPPA to redirect the www.portkey.org portal to
this page, or somehow update that portal. Lots of things in his RL has prevented him from doing that. One of those things was that he hurt his foot, so he needed therapy.
Besides, NAPPA himself would admit he tends to forget PK pending tasks.

One of my roles before (in '03-'05) was to remind him about mods' pending requests.

Other mods had that role too.
4. I ask about the chatbox because if we could install that here in the forums, then more people would probably join. Chatboxes are very user-friendly unlike IRC.

But that's only a suggestion. Now if you could perhaps make that PHP file to get it running, maybe we could ask NAPPA to upload it to PK's server. I'll have to ask you again for help in how to get that box to appear in our forums' HTML templates - give me the HTML codes for me to copy in the board wrapper.