Great input, Adriel, thank you for that – I hadn’t realised that we could give such wide access for blogs, I’d just lazily presumed we’d need to give access person by person. Ideal – I’ll do it set to intern with the blogs and see how it goes from there – thanks!

Aran, my top two thoughts would be to set up a suggestions page to facilitation discussion, and/or a blog page set to allow logged-in users to post blogs.
You will be able to have running conversation threads in either of these formats, and you can set access levels to “intern” if you wanted to lock them down to just your volunteers. If the pages are open and you encourage sharing, you can also pick up related conversation from Twitter in the reactions.