Herald - Paladin/Caster & 100% Shield Absorb

So I just started DKS3 with the Herald and I have to say, this Shield is amazing. It's saved my ass so many times , especially during those hard ganks from skelebobs. I'm just wondering is it fully possible to make a turtle build with this kind of shield or in this case be a Paladin of sorts with the Herald. (Sword & Shield). I was thinking of making a Defensive Heal Tank/Caster for my first play through, any tips? How well does Spear scale in the later game? I also picked Rusted Gold Coins over the Fire Gem, since it drops later on.

Also for their shield (which is amazing by the way) for the 100% Melee Absorb is that including melee oriented type magic as well? I mean I know it's a gray area to think about, but it's something I was also thinking about. The future build for this character was going to be with Twisted Wall of Light.