Impressions really can be deceptive. 
That's why I asked for facts. There is some mechanism that makes people see what they want or expect to see, which might be why we disagree on *this subject. You see exploding chests amd .... hmmmm ... maybe I should bring an archer along the next time, then I'll probably *want to see her/him blown up. 
As for your examples, I usually opens those chests before anybody (except maybe the clerik) has gotten any promotion, except for the ones in the tunnels in SC, and my guess is that the chest outside the training hall can be opened wiht TK without damage to the party, maybe also the ones outside the throne room, maybe even one or two in the rooms and the one near the entrance (I'll have to check that though). Add to that the chests in the tunnels. In the Haunted Mansion there are at least four chests that can be opened safely with TK, the ones where the corridor widens near the bottom of the staircase. I have a very vivid memory of chests exploding there on the first visit even with a thief.
I'm glad you mentioned disarm: if I decides to make some statistics on exploding chests and safe distances I should also bring a thief along for comparison. It's too bad that this RL stuff 
makes it nessessary to postphone the project.
