Well I have played out lots of test combats at different levels and ELs and when it comes to berzerkers I think that Berserker's mind and Berserker's toughness are imperative. With Berserker's toughness you can retreat from combat using a Move action and stoke fury with a standard action, healing yourself 4 HP. The round after that you stoke for a full action and get 8 more HP. This can also be used in battles; many opponents doesn't deal 8 damage per round with the berserker's DR etc.
If that fails for some reason (for example you are out of Reserve points or don't want Berserker's toughness), then see those extra HP as if they aren't there. When you are approaching the dying limit break off from the combat. If those HP didn't exist, your berserker would be dead anyway. If you think it's bad role playing to retreat when raging then the extra HP wouldn't mind, your character wouldn't retreat anyway and would get killed.
But essentially I think Berserker's toughness is the second most important berserker ability to take after Berserker Strength. You can wait for third level to take Berserker's toughness as well; at lvl one and two Berserker's strength only adds 2 and 4 HP, not enough to kill you after the rage.
If that fails for some reason (for example you are out of Reserve points or don't want Berserker's toughness), then see those extra HP as if they aren't there. When you are approaching the dying limit break off from the combat. If those HP didn't exist, your berserker would be dead anyway. If you think it's bad role playing to retreat when raging then the extra HP wouldn't mind, your character wouldn't retreat anyway and would get killed.
But essentially I think Berserker's toughness is the second most important berserker ability to take after Berserker Strength. You can wait for third level to take Berserker's toughness as well; at lvl one and two Berserker's strength only adds 2 and 4 HP, not enough to kill you after the rage.