I used to play Faery Tale Adventure on Amiga. The anti-piracy was code phrases around the edge of a paper map.

Not UNIX-like, iOS is real UNIX.

While you should probably fix your router, there are some workarounds that can work. If you have your own domain, cloudflare tunnels are really great. Similar option that doesn’t need a domain but requires a VPS or other hosting with a public IP is just a WireGuard tunnel to your service.

Literally everything. iMessage is a real messaging app with all of the bells and whistles. Blue means all of the features you want will work. Green means SMS, which is garbage.

iMessage gets you end to end encryption, read receipts, reactions, larger media sharing, functal group chats, and more.

RCS solves some of the shortcomings of SMS but it’s not a feature that Apple supports.