You're welcome! I like reviewing stuff, but I seldom have the time to do it properly (and I rarely visit the forum when I am not anxiously waiting for reviews myself ^^)
So, to answer your questions:
lib = library, as in sample library. In this case, Ministry of Rock 2
Exactly. Copy paste from another post where I explained it better: "To double track, play the same riff twice, with slightly different effect chains on each take, and hard pan one to the left and the other to the right. It'll fill so much more space! ".
I personally use Revalver HPSE, but I got it free with Shreddage (which is a great guitar library for Kontakt, but rather costly). I'm not exactly sure what to recommend you, I'd suggest you try to find some reviews only for free amp sims (or not free, as you wish) and see which one you like best.
I talked about it at the end of my review, and I suggested you worked first on the few "bad" notes (which should be rather quick), and then work with Ministry of Rock 2 to try and make your guitars sound better, both by playing directly with your plugin, and by working on your articulations.
Have a great day!