and if +Pell is indeed convicted of sexual abuse, then the pope will have no choice but to remove the cardinal from his Vatican office and probably his performing Mass in public, with other sanctions as well . . . 

Anytime a priest has an allegation made, he is removed from his post and he is stripped of his faculties until either a civil conviction, a substantiation of the allegations or an acquittal.  The removal of faculties comes while the investigation is ongoing, not after.