I see that the proposed feat tree was a little to ambitious so i'll stick to just one feat. Maybe I'll expend a tree down that line later.
Here is the all new and improved proposal:
Fury of the wolverine [General]
Prerequisites: Rage ability
Benefit: Every time you suffer in the same combat damage equal or greater than half of your total hit points you instantly fly into rage.
This effect only takes place if you are currently not sleeping, dying or unconscious or the damage you receieved removes this condition (or all if you suffer from more than one of these conditions).
This does not decrease the number of times you can enter rage per day.
You may try to ignore this effect by making a will save DC 10+ the damage from last attack you recieved.
You do not gain extra benefits if you are already in rage.
Normal: You can only enter rage a number of times equal to you daily used of this ability.