Honestly, IMO it's by definition real because we're all here and experiencing it.
Even if it is a simulation (I personally don't think it is, but wouldn't really mind if it were) that doesn't make it less real. It's still our reality, after all.
I can't prove to you that I exist, of course. But like, who cares about "actual existence" anyway? I'm clearly here and talking to you. Even if I were a simulation NPC or "just in your head", I'm no less real. Probably the more important thing is that I can't prove I'm not an unthinking NPC just following a program.
Then again, Occam's Razor. It'd be weird if you were the only one who was actually thinking and everyone else was just mindless NPCs. It's way more likely that we all exist and think independently (whether that be in a simulation or otherwise, doesn't really matter).
-- Frost
You can totally do that yeah!
We have our stuff set up so inbound VPS traffic (for HTTPS) comes in on port 4430, while LAN traffic is on 443. It's not done for firewall reasons, it's so we can pass the client's IP through with Nginx's proxy_protocol feature, but you could just make your local-only services not listen on 4430. Boom, done.
Fail2Ban on the VPS is probably good. On the home server, it might just lock out the VPS (since everything comes from there).
Anyway yeah, I've got a whole guide on this sort of setup! https://frost.brightfur.net/blog/selfhosting-with-a-bounce-vps-part-1/
-- Frost