when my Windows 8.1 will reinstalled from scratch all boot entries like grub would removed
Use EasyBCD (free version) in Windows 8.1. It can restore Linux in one click.
Do you using linuxmint as of today ? If yes can you tell me it's pros and cons.
Linux Mint is very popular and probably best linux like i read
Is mint more user friendly than Ubunthu?
Linux Mint is a fork or Ubuntu. When Ubuntu became popular, they started commercialising it. Like adding Amazon suggestions in search. Since Ubuntu is open source, a group who are keen on keeping it away from compromising user discretion began forking (or you can say simply copying it without ad codes under the name Linux Mint).
Most software if not all which work on Ubuntu will work on Linux Mint as well.
Will a Windows user be able to manage everything? Or is there still a lot that needs to be done through command line?
Unlike Windows, you can choose how your desktop environment looks in Ubuntu / Linux Mint. All you have to do is install a desktop environment ( which again has themes to make it similar to Windows) like KDE, Gnome Classic, Cinnamon (I prefer this), Gnome etc
Gone are the days when everything is done through terminal (command line) in Linux. Ubuntu / Linux Mint is the closest thing in Linux you get to Windows.
You can install software using Ubuntu Software Center which is more like Google Play or Apple App Store. The updates can be installed through Software Updater.
Even if you need to use command line, it is pretty easier than you think. Honestly, in earlier days I had no idea what the command I am using means. All I did was copy paste and simply press enter a couple or three commands in Terminal ( that is what they call it for Command Prompt in Ubuntu).
Feel free to PM me / start a thread with tagging / or use this thread if you think I can be of some help.