Grimrock

Unarmed Combat defensive benefits: 40hp, 40 evasion (20 from +10 dexterity bonus)
Conclusion: Unarmed Combat is barely overshadowed by Dodge as a defensive skill until the player reaches 50 points in Dodge. Therefore, the Unarmed Combat expert enjoys near optimal offensive and defensive capabilities for (appoximately) 75% of the game.

Minotaur offensive/defensive benefits: +5 strength, +4 vitality, Headhunter skill (+3 attack power per skull carried - maxes at +15)
Conclusion: the Minotaur is allowed to spend his skill points defensively while maintaining an ability to gain modest offensive capability thanks to skulls. His penalty to dexterity may be overcome by usage of thrown/missile weapons.

Aye, Minotaur's are definatly THE choice when it comes to throwing or missile weapons.

Characters with 0 evasion—like mages in the back row—might as well equip heavy armor. Not sure why this did not occur to me earlier! Tank-mages for all.

Front-line Minotaur tank: 25 Armors skill for doubled shield evasion, 30 Unarmed for the 20 evasion, evasive trait
Wears heavy armor, fights unarmed or wields throwing axes

Secondary tank is free to wear Lurker set

But the evasion does go negative (I was never quite sure if this mattered, but I always thought so)

It seems that early-game monsters have a chance to miss characters with 0 evasion. It is assumed that later on monsters get more accurate and a character with 0 evasion would perhaps take every hit.

You make a good point - we don't know the base numbers or formulas for accuracy and evasion.