A day after the Diocese of Rockville Centre stripped former Catholic church official Msgr. Alan Placa of the right to serve as a priest, his friends spoke out to defend him against allegations that he abused teenage boys. Placa, who has denied any sexual misconduct, was a key official in the diocese's handling of complaints of sexual abuse. Richard Tollner, 43, who is now a mortgage broker in Albany, went public in a Newsday story with the charge that Placa abused him 25 years ago at St. Pius X. Preparatory Seminary in Uniondale. The story detailed how Placa allegedly handled complaints about abusive priests, transferring some of the troubled priests to other parishes after treatment.  Placa got special permission from Bishop William Murphy to preside at the funeral Mass for the mother of Rudolph Giuliani.  It was a one-shot thing because he is such a close friend of the Giuliani family, said Joanne Novarro, a spokeswoman for the diocese.  Placa, a childhood friend of the former mayor, appealed directly to Murphy for the temporary reprieve.  The suspension barred him from saying Mass, hearing confessions or administering the sacraments.