Noticed another possible bug, my thief is not able to hide in the shadows when positioned in the front row, but if he's in the back row, hide & ambush commands work as intended. In the in-game documentation, the hide & ambush options are available "even from the back row", which suggests that the front row is possible as well. Is this an oversight, or are thieves and ninja only intended to hide from the back row? If they are only meant to hide and ambush ONLY from the back row, then the documentation should be updated accordingly.

Additionally, I've noticed that my thief in the back row has been physically attacked during combat from time to time, and I thought that the back row was safe from physical attacks?

Thieves only hide when in the back row. Most definitely not. This is why one of their function is to Parry.