I don’t know how safe this is, but what I do:
- Make a local XMR wallet, backup, and host your own blockchain
- Buy regular crypto, say LTC, from a legit exchange with KYC
- Swap that to XMR on an anon swap/exchange, storing in your wallet 3 (optional). Move from your first wallet to another, for extra safety???
Spend it where you can, not many places. BTCPay server, which can be self-hosted, supports it, so there are options.
It’s feasible as long as all the stuff you want to auth supports oauth, oidc, or saml. It might be a bit overkill for your use case, unless you have a bunch of services you didn’t mention. Keycloak has a bit of a learning curve, but works great once you get past that.