Hi, first post from a long-time LUGRadio/BV listener.
Just my £0.02 on the two main issues.
Elementary Appstore will fail, like all other Linux appstores failed. Even Nokia tried and failed. Github integration is a good idea (and one would hope they will add BitBucket soon), but the fact of the matters remain: someone who went to the lengths of installing a Linux desktop just to escape a commercial ecosystem, will simply not value commercial propositions beyond the occasional tip jar.
What I'd rather have is a way to pay OSS developers to add a feature I want. Say there is an email app I like, but it's missing support for GPG; I pledge £20 for that, and when the developer delivers a working build with that feature, the money goes to his account. Make the process streamlined, possibly even with an incentive to componentize software (I can install the build with GMail support for £5, the one with GMail and IMAP for £10, and the one with them and Exchange for £20). That would have the side-benefit of emerging features people actually want, which could drastically cut down on typical OSS flamewars and bikeshedding. (note: of course developing a feature is more expensive than £20; the point is that multiple people would pledge, hopefully reaching more realistic numbers in aggregate). Don't make me go to a bugtracker or even to github - give me a consistent interface (right-click on the app -> Ask for feature / View requested features, then have a simple and consistent interface to pledge).
This is not easy, but IMHO it would be a game-changer in a way that yet another (empty and lonely) tip-jar will never be.
Guest-presenters: yeah sure. It's actually more entertaining than traditional interviews, as long as you stay close to the tech sector (I'll be honest with you, I really did not care for the film segment).