Quick guide to stats

[Narky Sawtooth♪]

Vitality - Useless, doesn't increase survivability at all.
Luck and Charisma - Extremely powerful, so much so that even at 0 you're basically golden. They tried to make this worthwhile and it backfired spectacularly. Actually better for survivability than Vitality.
Strength - Good, about 70 points in it takes care of most enemies that give your guns trouble.
Intelligence - Good, but requires about 110 points in it to hit the break point on most enemies. Big guys will go down much more easily at that point.
Agility - Doesn't really do anything.

tl;dr only Strength and Intelligence matter.

Edit: Oh, and the help screen explaining what the stats do is actually wrong.

[Ackranome]

Vitality is great - having high HP equates to having higher regeneration - the smart way of playing is to max your vitality out when you create your initial character and dump stats into Luck afterward.

I haven't figured out what Agility does as it says "movement speed" but I barely notice anything when I put points into it.

[Nevoras]

Also you need stats like vitality for some equipment to use.

[Narky Sawtooth♪]

Oh, right. The stat reqs. A-whoops.