That cblink class is just a convenience, it does what it does, if you want to do something custom with colorbox you'll need to wire up an instance of it yourself so you can control everything about it. IncludeColorbox will include the main script so you don't have to add that yourself but you'll need to study the documentation for colorbox and wire up your own instances for custom things such as video.

The Google Plus button was introduced in version 2.3.6.7, it is available in the blog and it can be used as described in the article. The 2.3.6.7 release was patched with a few fixes on 2011-07-20 but those fixes were not related to the google plus button, still you might try updating if you installed it prior to that. As noted on the codeplex page:

Updated 2011-07-20 patched to fix a bug in the Contact Form and a script error that could occur if running in a non root site
the only files that changed are:
mojoPortal.Web.dll
mojoPortal.Features.UI.dll
mojoPortal.Net.dll
/ContactForm/MessageListDialog.aspx
/ClientScript/jqmojo/jquery.layout.min.js

Best,

Joe