(a) Unless excused by the court for good cause, the petitioner and the proposed guardian shall attend the hearing. The respondent shall attend and participate in the hearing, unless excused by the court for good cause. The petitioner and respondent may present evidence and subpoena witnesses and documents; examine witnesses, including the visitor; and otherwise participate in the hearing. The hearing may be held in a location convenient to the respondent and may be closed upon the request of the respondent and a showing of good cause.
(b) Any person may request permission to participate in the proceeding. The court may grant the request, with or without hearing, upon a showing of good cause and after determining that the best interest of the respondent will be served. The court may attach appropriate conditions to the participation.