I'm in the process of hardening caddy. It's a work in progress, as I'm new to caddy. I always used Nginx. But I decided to give caddy a try as I saw it recommended a LOT.
protip on this front: Turn off hiding file extensions in file explorer. Then you will see if it's an exe or not. I don't know why tf windows turns that on by default. It's stupid.
Get a Kobo. They're awesome for reading. They feel like paper, like you're reading a real book. And it's pretty simple to sideload books. Plus you only have to charge them every few weeks, up to a month sometimes.
I like zen, but their plugin section needs work. With the layout of Zen being what it is, when you display plugins on the toolbar, it distorts the UI and looks funky.
I don't know, but I expect it's having an issue because i assume the port is forwarded from your router to your caddy, but then the caddy server it redirecting back to the router. I don't know how you'd get around this. but that might be a starting point for your research.
ETA: Also, it's a bad idea to expose your consumer grade router to the internet. VERY bad idea.
You have to think about the extra costs, like power use , loudness etc. I have no idea what your server would be like, but it's something to think about. FWIW, i reused my old desktop (it's pretty beefy) into a server, but i run a pi now, because it was costing me a fair bit to run in power usage.
/m/catsareliquid