No, we will not do any of these things, as we can’t and don’t want to. This means that effectively, “our” 30% is a lot less than the 30% charged by other platforms with all of these other restrictions in place.
However, when we are processing payments we’re not particularly interested in whether proprietary applications do, or don’t, choose to use our service. The purpose of what we’re doing is providing additional economic opportunities to free and open source software developers. Providing proprietary applications a marketplace is a convenience to users and accepting that people have other opinions and requirements about licensing.
It may suit some particular larger / niche proprietary apps to use our system if they tend to rely on similar services on other platforms, but I expect that the majority of proprietary apps on Flathub will be clients for cloud services, and hence remain free of charge, with paid portions taking place off-platform via subscriptions or other in-app payments (eg Spotify, Steam, etc). I’m fine with that. Hunting them down and forcing them to use our stuff so we make more money is leveraging a dominant position we can’t - and don’t want to - have.