So I have two questions.

1. Should I constantly be casting stoneskin? A tank I played with said I should use it often on everyone. But it kills my mana during boss fights! I usually prefer to use it on myself or if someone is about to take a big hit ( if I can cast it in time...) To give some background of where I was asked to do this was during Wanderers Palace... But the runs I performed before went smooth without spamming it..

2. Should I take time for a bit and work on getting an eye for an eye?