What expense? Adding one more thing to track about you, especially something they already know and essentially just need to verify, cannot be that expensive.

CDDL not mentioned. Have fun illumos!

WireGuard doesn’t work at all because it is blocked in OP’s country. OP wants an alternative. Dumping all security and encryption is certainly an alternative, but I am certain that this is counter to what OP is trying accomplish, given their initial choice of Tailscale (WireGuard on steroids).

Sure, but they shouldn’t.

You will learn a ton. Also, you will spend a lot of money hosting an activitypub instance. I run a server for fun, and it’s about $40/month to handle the absolute firehose of assets I receive 24/7.