No, a person could confess a crime to his lawyer, and the lawyer isn’t eligible to be called to the witness stand because he represents his client and so is legally viewed as being the client. Thus the 5th amendment would come into play.
Nope. Once defendant pleads "not guilty," confession of commission of a crime to legal counsel makes said legal counsel accessory after the fact, criminally liable if said confession is discovered, obligates defense counsel to recuse, bear witness.