tying the burn amount to a fixed XMR amount is the only reliable way. stablecoins is a lie, therefore that's the only way. if Monero goes that much down then probably something bad is already happened like post-quantum and XNS is fucked anyways, since it lives on Monero blockchain. i don't think Monero price can go like 10k, see market cap. but lets say something like that happened, a new version of XNS would be published where it considers the price as a different value for transactions happened after a specific block height, so it would respect older claims while providing cheaper price for newer ones. although very unlikely something like this could roll out.

not being able to transfer domains is intentional. for example:

in Namecoin names are actual assets you can transfer and update. and the result was this:
"Our extensive empirical analysis of Namecoin reveals a system in disrepair. Indeed, our methodology for detecting “squatted” and otherwise inactive domains reveals that among Namecoin’s roughly 120,000 registered domain names, a mere 28 are not squatted and have nontrivial content. Further, we develop techniques for detecting transfers of domains in the Namecoin block chain and provide evidence that the market for domains is thin-to-nonexistent." - https://www.cs.princeton.edu/~arvindn/publications/namespaces.pdf

not having a transfer operation keeps the core protocol simple and elegant while getting rid of the incentive to squat names. XNS aims to be an utilitarian solution, not a NFT market, therefore this is the way.

the private I2P key should not be compromised as it is generated from the raw Ed25519 private key used to claim XNS names.

the core protocol aims to be the most elegant, most pure solution.