Is it more secure to run linux as a second operating system for this purpose?
It is always more secure to run Linux then Windows. You should definitely upgrade to Linux as soon as you can. You can use a Virtual Machine if you really need some windows program, but you have open source alternatives for almost all software.
While Linux is definitely more secure, there really isn't any need to install Windows. For most people, Windows is still more comfortable and easy to use. If you were to ask someone to switch to Linux, the UI and functions would all be vastly different. I don't see a problem as long as you don't run any suspicious apps or go to any random website. If you patch your computer regularly, it would be rather secure, given that Wannacry infections was also due to users not patching their computers.
In order to become one of the bitcoin community, I believe that one must also have the knowledge about computer or any computer related background for him or her not to have a hard time in using and gaining bitcoin. It needs to be a requirement.
I really don't want to go offtopic. I didn't have knowledge about computers nor Bitcoin when I first entered and I learned it through the community here. We are all here to learn. Kindly refrain from commenting if you are not going to address anything in the thread.