HUD is for losers!!

Naa, is not for losers but is not for me. What I want to make clear to the people that are reading this blog is one thing, what I'm trying to achieve is not a super-realistic graphic, but a clean graphic with no HUD at all, using other way to indicate to the player what s happening to his character.
How I'm gonna achieve this? Post-Process is the answer.
My plan is to make active different post process depending on the level of life and stamina of the pawn.

Post-Process activated by the healt\stamina of the pawn left
	Healt Based
		Pawn.Healt < 60%				Darker Corner
		Pawn.Healt < 30%				Desaturation
		Pawn.Healt < 20%				Blood on the screen
	Stamina Based
		Pawn.Stamina < 60%				Vertical oscilltation
		Pawn.Stamina < 20%				Blur, Vertical oscillation, Deep Breathing

This is the basic idea, of course I dunno the complete script for the moment, but I'm getting to it. Only one thing make me wonder if it will work. Will, all those post process effect, slow down my game, to heavy to be run smoothly?
I also seen that UDK implemented, in their last releases, they have implemented an oscillation of the screen, like if the player was actually breathing (which is really cool).