@Onscreen5341 pretty much covered it.
I’d note that the VPN can cover pretty much all of those things. Proton VPN can block LAN connections (although it seems perhaps not on all platforms), provides a kill switch and a VPN would almost always uses its own DNS service much like your ISP would.
So finding a good VPN provider with the correct settings is a useful way to cover most of the potential problems.
I have come across networks where I struggle to connect to VPN’s (Proton and Windscribe on free tiers as I rarely use VPN). It’s unclear whether they’re actively blocking them or if there is some other issue where they just didn’t bother setting everything up very well.
My go to in that case is often using Cloudflare 1.1.1.1 Warp. I don’t expect the same protection from it, but it does at minimum provide a DNS and pushes much of the network traffic to Cloudflare making it more secure. I’ve also “suddenly” been able to connect to and switch to VPN once Cloudflare was active.
Two remaining problems are http traffic, which has no inherent security and could easily be tampered with and what anyone around you can physically see on your keyboard and screen.