(...)
However, is it possible to install two OS in one PC?
MufasaR is right, dual boot is the solution for that.
Either you have 2 hard disk drives or just make some partition just to able to install your two operating systems.
5. good for developers
I'm also planning to move in Linux if ever I will have some windows laptop soon and I'll just install some Linux operating system on it instead of windows. Since for now, I am using Mac OS and using it for developing in pretty also awesome, I think it will also differ which field you developing, like you are more on website development or mobile development, etc.
Lastly, self-awareness and education still good, even which OS will you use if you are dumb enough to fall in those some exploits/ransomwares you will still be a victim. I've been using Windows OS for a long time and didn't even try to fall in some exploits.