Meersbrook Hall could be run by a local group, but stay in the ownership of the council.
Robert Hanson will now sit as an independent after his Reform membership lapses.
Charlotte Killeya has melanoma and is helping launch free sun cream dispensers in Crookes.
Sheffield and Barnsley councils have seen several resignations since local elections in May.
Officers will patrol Sheffield neighbourhoods and parks and issue fixed-penalty notices.
Tom Hunt says he will not stand for re-election in Walkley, where he was voted out three months ago.
The Green Party's Andy Davies, who beat Labour's Tom Hunt by just 73 votes in May, is stepping down.
Inspectors tell Sheffield Council to explore urban sites for development, instead of city green belt.
The Grade II-listed mansion has been empty for a decade and has fallen into disrepair.
