1) soldier morale

2) soldier and champion loyalty

3) some resistance to mental attacks (also affected by Wisdom)

4) personal morale and loyalty (also affected by Wisdom)

5) optional choices (via dialogue) to avoid some battles (other choices offered with high Intelligence or Wisdom) ... different enemies are more impressed by a different stat, and some battles are unavoidable. When an attack screen comes up (not from a major faction) auto-battle, manual-battle, or conversation ... also can work in Text based/ conversation based quests

6) effectiveness of stealing/theft/pickpocketing

7) +chances of having children

8) +chances of having bastard children (even before marriage) (although, if you marry the mother of the bastard ... well their not a bastard any more)

9) +Diplomacy

10) increased reward for "favor" quests

11) increased valor for refusing reward (if Valor is enabled)

12) increased valor for releasing prisoners (if Valor is enabled)

13) increased effectiveness of Charm trait

14) increased effectiveness of Illusion spells

15) increased effectiveness of Charm spells

16) slightly increased effectiveness of non-Charm mental attacks (also affected by Wisdom)

Either way ... some combination of Intelligence and Wisdom should be used to increase Perception (find hidden things)

with a proposed "trap-finding" schema ... Intelligence increased your chances of finding a trap "per attempt", while Wisdom increased your number of attempts.

Although ... maybe you should be wearing a rouge pack or a scout pack to even have any chance of finding traps??