Apologies accepted.
After some testing Wits do impact healing, it is not written anywhere but it does. The same as Phy impact damages, Wits impact magical damages and healing so train your mages/healers.
"have you/did you have any rare "near impossible" enemies? "
Early on a Troll and a Golem are quite formidable foes but not unkillable if you manage to have offensive spells, I would recommend to stay away from the Ancient Jungle. The creatures there are nasty.
Assassins are dangerous but you encounter them only in Bandits Forts, with my current team I can vainquish them.
Rebels? not particularly? they are cannon fodder against my team, I'm faster, more precise and can evade them sometimes. My spells either burns them to ashes/ cut through them easily, my fighters can cut them down and tank them too.
In this version 0.5.4 foes with unique traits are indeed more dangerous, beware of them.
My combat team is enough to deal with any threats in early game (till elections) afterwards you would need to train and give better equipments to keep things smooth.
For the Guilds REP there is no notification in the changelog but you can see it in the Journal.