Use wp_localize_script var
Rename ajax my_global

Renamed for improved readability. This var sets the .ajax() global item.
Fix textarea ID

1. Removes two instances of "id" from textarea tag (id="comment"
deleted.
2. Uses more relevant textarea id for ajax submission
Temporarily disable "time handle" js

Can't see any need for this functionality...
Fixed entities code (missing ; )
Use the user's Display Name, not nice name
Remove invalid "name" attribute from comments container div
Enqueue styles in its own function

This allows more control over the order in which stylesheet is added to
header.
Implement wp_localize_script

The "doing it right" way of passing vars to the javascript file.
Increase priority of wp_enqueue_script call

The idea here is to ensure that our script is loaded after anything
else. Probbaly overkill as the wp_enqueue_script "deps" argument will
normally take care of this.
Remove js data-template attribute

Removing this because:
1. It isn't defined and throws a js warning
2. It isn't needed
Add PHP comment to remind me...

Just a reminder that the INPUT field in the comment template is for the
nonce when the existing comments are loaded via ajax.
Added inline PHP comment to remind me...

Reminder that the inline_comments_ajax_target div is the container for
the comments fetched via ajax.
Added some newlines for readability...

Note: final js file will be minimised for production.
Wrap comment in a paragraph tag

Improves layout of avatar and text.
Remove template_redirect action call

No longer needed since enqueuing of scripts and styles has been
reorganised in plugin.php
Function moved to plugin.php
Re-ordered the comment template code

User name now appears before comment text
Temporarily remove conditional tags for scripts
Play with fadeIn setting