A little cuestion

2 libraries? you mean 2 accounts?

No, you can't move Steam games from the library of one account to the library of another.

No, it's not. You can use family sharing with your second library though.

Why not? Ctrl-x ctrl-v

Just make a backup from the steam folders before u move them

and then move them to another disk, this is the only way

You use the cue stick to hit the cue ball.

It is possible with some manipulations with steamapps folder. Just move (cut and paste) the game files from one steamapps\common in one library folder to steampps\common in another, delete the game in Steam and re-install it in the library you pasted it into. If everything went smooth, it won't redownload the game.

Yeah, just move the appmanifest file and game data to the other folder! Should work o.o