You can install Synaptic in Debian. Problem solved? I love the terminal so this isn’t really my fight but you could spend some time to make Debian GUI-based if you wanted to.
Also LMDE exists, which Mint-ifies Debian and gives you a GUI option for basically everything you can imagine.
I’m not totally sure of the wisdom involved in gating content when ActivityPub and the Fediverse are still so new and niche.
If you’re putting out premium content that doesn’t affect the existing communities, whatever, I don’t care. But I do have to wonder how you’re actually going to make money when most users are used to free content.
Wouldn’t it be easier to use Ko-fi or similar?