??? A defendant can waive a Preliminary Hearing only if the Prosecutor agrees to waive the Hearing. There may be conditions to the waiver; in any event, the Defendant is giving up some rights in waiving the PH & most attys will advise defendants not to waive prelim. (it's a glance at the Prosecution's witnesses, how well they testify & the Prosecution's trial plan).
Defendants have to be present at the Prelim. If Def is ill, the PH can be continued....