I went down into Dungeon Level 2 and used Stone Wand in front of myself (I haven't been playing long and I'm still working out what everything does). A column of stone appeared in front of me, which is presumably (one of) the desired effects of the spell. However, I could not turn and go back upstairs, even though I was still standing at the bottom of the staircase with no stone in front of me. I could move to the side, so I wasn't stuck. Don't know if this is a bug or not. Sorry I didn't take a screenshot at the time, but I'll try to reproduce this next time I'm playing if this is a puzzle rather than a known bug or feature.
I'm not exactly sure what you mean, but any movement issue with the pillars aren't a big deal - the pillars go away after some turns.
Hard to say for certain without having a screenshot, but I suspect there was a monster blocking the staircase. Wands cannot target empty spaces on the floor. There must have been a monster there in order for you to use the wand. When the wand activates it creates a wall on the monster's space, does damage to the monster, and then usually displaces the monster by a space or two so it's no longer on the same space as the wall. Typically this results in the monster being further away from you, but I'm pretty sure I've seen the monsters end up pushed the wrong way, and I know for certain that at least once a monster just stayed under the wall for several turns and then eventually stepped towards me as if the wall were never there. So, I suspect the wall displaced the monster onto the staircase. Thus the staircase was blocked. If the monster was short enough, it may have been difficult for you to see it behind the wall. Alternately, that monster could have been knocked away from you by the wall, and then a Dead Head (one of the monsters on floor 2) could have blinked (teleported) onto the staircase. The knockback effect of the wand can also affect terrain objects, such as grills, statues, candles, gargoyle traps, etc. One of those could have been displaced by the wall, and ended up in the same space as the stairs. Some of them are pretty small and hard to spot. They would then make the stairs space impossible to enter.
