A significant majority of OH users are running on some flavor of a Debian based distro (Ubuntu, Raspbian, openHABian which is based on Raspbian). So you will have a lot more people able to help with environment issues.
You will also be able to use openHABian, which if you follow the manual instructions will give you a standard environment already configured with OH and support services for you, saving you a lot of time and giving us here on the forum an assurance that you haven’t accidentally messed something up with how you installed everything.
OH itself is Java so everything gets updated at the same time. There is only the one package.
Lots of users are running pretty stably on Windows. From a technical perspective, there is less automated on Windows in the install and configuration (e.g. no apt-get install, no openHABian, though there is a Chocolatey package). I wouldn’t recommend against Windows for reliability. I mainly recommend against it because more people will be able to help and it is easier to get everything running on Linux.
Yep. Though that is another vote for Ubuntu because a lot of those (not Zoneminder or minecraft) are installable and configured through openHABian. It’s nice to have a one stop shop.
But @SkipMorrow, don’t underestimate this. I started with OH and now have about a dozen services. I eventually had to upgrade to a desktop server running ESXi.