Few questions Before Installing

Hello,
First of all You developed a Great Plugin, i gave Google Page Insights test and i really dont know what Google is talking about in Results, Even i never heard those words before.

One of ElegantTheme Article refer your Plugin, Its really good you fix most of the issues which Google Insights list’s.

Before adding the plugin, I have few questions,
How this Plugin work, Like do it update Theme Files and wordpress files code to make them more optimize? or it create few files, which loads instead of WordPress files, something like super cache plugin do?

If this plugin updates the Theme files or core files of wordpress, what happen when i update the Theme/wordpress, do i need to run the plugin again?

I also use many other wordpress plugins, Do it also update files/codes of those plugins?

If this plugin update my WP file/code, what happen if something went wrong after activating it, how i will get the old website again?

Sorry for such newbie questions but that will help me to understand the plugin batter before installing it on my money website, hope you can understand, thats important for me.

Thanks.

https://ww.wp.xz.cn/plugins/wp-performance-score-booster/