That election is why the headline 9% overstates the real bill — the rendita base is usually well below market. Prima casa relief cuts it to 2%, but only if you move your residenza to the comune within eighteen months.
Condominio arrears transfer with the flat. Ask for the administrator's statement, the last balance and any voted works before you sign the proposta, because a facade job decided last spring is now your facade job.
You need a codice fiscale before the notaio will close, and again afterwards for the utilities and the IMU filing. Historic-centre buildings carry Soprintendenza constraints that cap what a renovation can legally deliver.