Concerning the cron job, you might want to take a look at http://deadlytechnology.com/silverstripe/scheduled-tasks/ However, this assumes users can set up a cron job, which might not be possible on shared hosts. Drupal has a module called Poormanscron, which replaces this requirement and triggers jobs by requests to the website. However, this is rather a standalone module and beyond the scale of your project - just to point out an alternative. How you want to approach this is up to you. Here's a tricky question: You'll get an endless stream of activities from FB - how do you want to add them to your site? Keep the last X entries and remove the others, post everything to the blog module where every entry is a dedicated blog entry,...?
I am still working on the details of the Facebook --> SS Site implementation.
Activities can be prioritized like Check-ins can be ignored and small status updates, events that the user is attending can be compiled in the timeframe of 12 hrs(user dependent) in the form of a single post while a large post can be posted in a single article form.
Another tricky question: How do you handle updates to your site? If it's new content, you'll probably want to post it to FB, if it's a minor correction you probably won't (as there are no updates to FB entries). Do you want to handle this automatically, provide a checkbox ("post to FB"),...?
I think an implementation like Tumblr does for Twitter will be fine where we can provide a checkbox for the user to selectively post on Facebook.
Ok - some more details in the final application would be nice. If you already know how you'll do that, we don't need to discuss it here right away. I'd only want you to have a good understanding of each task, so that we can establish sensible estimates for the implementation.
The crucial thing in the photo module thing would be to control photo access by the module. No one would want his each personal photo to be posted on his blog so we would have to take care of that by enabling a particular album access from the user(this thing is also a valid concern for status updates). & also we will have to copy the images on the site's server by using the access token.
What's the scope here - can we only comment on pages or also on DataObjects? You might want to take a look at SilverStripe's comment module (which has been part of core, but has now been moved into a dedicated module) for possible solutions.
We can also make commenting possible on DataObjects but as the way i see it Facebook comment system works on URL so every comment thread is attached to a specific url. We can also enhance this by making an option for logging in to the present commenting system using Facebook credentials and then posting comments(Disqus works in a similar way). I will check out the commenting system to work on the finer details
P.S. In the spreadsheet no mentor has shown interest in this project so wouldn't pursuing it be futile. Also, is there a preferential treatment to early application submitter.