As I think: Yes, it should be monitored, specifically when anyone is conducting the trial for toxicity profile of drug.

Just like placebo (which is used to nullify positive psychogenic response), Nocebo could be useful to nullify Negative psychogenic response...

Yes, it should be.

Yes. It is always monitored, because in the placebo arm we also monitored adverse effects. Nocebo effects are the adverse reactions of the placebo that also exists.

Yes, it should be when possible but not always the case, very often there is no placebo arm, especially in phase II and phase III clinical trial.