How much % evasion do mirage 1 ,2 and 3 give?

1.) what's the point of having elemental defences on ur shue..when they dont get added up like attacks?
2.)Is it possible for u to lose ur ss when u die?
3.) Is it faster leveling it with a noob character? and
4.)HOW CM I CAN TANK DD WHEN I CANT TANK XPLODE!!!!!!

What on earth are crystal of stability and crystal of brilliance used for?
If anyone knows please tell me.