Shield toss is based on your armor, like reactive armor. So your mage will have to put points in strength to wear armor that will allow the shield toss to be useful.
Nope.
http://divinityoriginalsin2.wiki.fextralife.com/Bouncing+Shield"Damage is based on the Physical Armour of your shield."
A bit different with Reactive armour :
http://divinityoriginalsin2.wiki.fextralife.com/Reactive+Armour"Damage is based on your current Physical Armour."
And I don't know why you are talking about stuff like "enemies are nearly dead with my ranges, my tank finish them when they are close" or "I have tentacle whip" --> a 2h can do and have the same. With more damages.
