If our BtcFn-Node receives in fact such payment to this address, then they will act as the payer says basing on reading the label;
The label is not public. You can't easily pass messages via Bitcoin.
The idea is OK. I would have just used plain text instead of HTML. Bitcoin sends blocks in chunks of 500 -- splitting in chunks of 10 seems excessive. I don't like having to convince someone in the system to pull data from me.
Hi, thanks for reading in detail.
The payment idea would work though

The payment is to given node. It is simply an ati-spam tool (to not have trouble like Frost).
Example: New node B joins network, and want popular node A to notice it.
Node A fortunatelly does offer such thing, for small payment (e.g. 0.01 BTC). Node A publish some Bitcoin address (of itself, or of the admin, or of admin friend, whatever).
Node B pay to this bitcoin-address related to node A, and node A will be somehow notified about the transaction and will be able to read the label.
The bitcoin addresses can be connected to BtcFn node, but also can be separated, in example friend of admin of node B can pay to friend of admin of node A, e.g. using TORed node to make the payment, or using another BtcFn node (other then B and A). All is possible

Eventually though somehow the payment TX will reach a miner, will be incorporated into a block that some other BtcFn node D will pull into freenet, this will be observed by freenet-only, reading-only stealth BtcFn node X that belongs to admin of also node A, and in the end node A will observe node B to honor this payment. Even such scenario should work eventually
