Uh, did you ever use the shield? It's completely inferior to every other class in every way - my suggestions would make it more balanced and less of a death trap. As it stands, using the shield WILL get you a negative K/D, 100% guaranteed and no matter how well you use it. How is that balanced?
The HP bonus is only active when you're actually shielding, of course. I suggested it because when a normal player turns a corner, he can do so with his sights up ready to take on anybody from any angle. When a shield guy turns that corner? Yeah, not so much. He can hold the shield up but if the enemy is in an unexpected place, the shielder is dead faster than a guy who can shoot back is. Shooting back moves their sights and makes it harder for them to kill you and stuff like that, whlie standing there on the corner holding your shield does fuck all to him.