Hi Neil,
If blogs are going to be an important part of your curricula, it may be worth considering alternatives such as setting up a Wordpress network (It's easy to do with Wordpress, just a couple of settings to change after installing). I used it for this pilot project: http://wp.matbury.com/about/ Buddypress is also worth considering: http://buddypress.org/, Elgg: http://elgg.org/ (Has some integration with Moodle), and Mahara ePortfolio (Has good integration with Moodle): https://mahara.org/ Mahara also has a suite of plugins that support the CEFR: https://wiki.mahara.org/index.php/Plugins/Artefact/Europass Elgg and Mahara are more geared towards education and so have more appropriate tools available to learners, teachers, and admins.
My apps integrate with Moodle but aren't part of it. It's possible to deploy them as standalone apps in web pages, or even compile them as mobile apps. However, the easiest way to deploy them in Moodle is with the SWF Activity Module which is a free and open source plugin that I developed and maintain: https://moodle.org/plugins/view.php?plugin=mod_swf I've developed some free and open source apps that come with it too: https://github.com/matbury It's also a great video player (Uses the free and open source Strobe Media Player, part of the Open Source Media Framework). Here's some demos on Moodle 2.5: http://m2.matbury.com/course/view.php?id=3
However, there's a bug somewhere between Moodle and the AmfPHP API (that communicates with Moodle) that prevents apps from interacting with Moodle's back-end. The bug only comes up with PHP 5.4. With PHP 5.3, everything works fine.