In the name of Kronk, ahahah! You make my day with this! Anyway, I knew someone could fill triggered by these words, and that's why I put it in that way. Ordinals obviously are just an option, I did not say is the ideal one, not Ii think is the most sustainable. Your nostr image host solution could be much more efficient and useful. BTW I don't see why @SN should not implement it... or maybe is already there?
Secondly
You are right on this too, I probably forgot to mention the built-in multisig functionality that can definitely be used for each transaction in steps (1) and (2). My mention to covenants was explicitly to automate somehow the payments a long time, in this case on a weekly basis mentioned in step (3). What I'm assuming is that covenants interact on signed on-chain transactions and support it until the variables are filled.
Lastly
You are totally right. The "trustless" was obviously referring to the whole process of creating an Ad here on SN, and don't trust any third party to have the deal done. This excluding point (7). It wanted to be just an option and could be easily excluded from the process.
I'm not setting here the standing stones of the process, just an idea to build on and exchange opinions to make it available somehow. True is, I mixed many things together without knowing the working details of them, including the covenants.
Summarizing
Ad-post created on SN together with an open agreement as onchain transaction signed by the creator (the owner in this case).
The other parties validate information and its interest, signing the agreement
Covenant is responsible to deliver the funds as established in the agreement (on a weekly basis for the next two months)
This could be done before step (2) and at the end of the lease with ordinals or nostr-image-host or any other solution able to host images in a decentralized manned with timestamp and other relative metadata
In case of any issue, a new agreement might need to be stipulated, so this will be a new multisig process linked to the original one but not able to break it.
in the best case scenario, when everything goes well: owner receive the full amount initially agreed.
This is a fully optional step, and if both parties do not find an agreement, I assume the first agreement will continue going until competition. If there's a disagreement, both parties should initiative a new dispute (contract), but this as well will be not affecting the original one.
Many of us probably are thinking: in two years, the value of bitcoin will be changing a lot! That's your problem, because you're still thinking on fiat terms. Fiat change value too.
Firstly
Secondly
Lastly
Summarizing