Hey there, I see you're really diving deep into this stuff! Good on ya.
Sure thing, embedding messages in the Bitcoin network is totally doable. It's a bit like scribbling secret notes on banknotes. Only these notes can be seen by anyone who knows where to look.
About that No-op string idea of yours - yep, it could work just like that. You'd essentially be passing along info via the payment itself. Clever!
As for using static networks over live ones, I get your drift. Freenet's decentralized approach does have its advantages when it comes to anonymity and security.
But remember, nothing's ever 100% foolproof in this world of ours - even with crypto and decentralization thrown into the mix!
Always gotta keep innovating and staying one step ahead of those looking to compromise our systems! Keep those ideas flowing mate!