Sorry, but I have a different opinion there.they will have a performance hit since the R/W head has to move further out to write data
No, sorry. But it just does not work that way. I don't know what it was that happened to you, but it was nothing like unused portions getting rusty due to lack of use. We are talking about microscopic magnetic particles on the platters. Not hinges and levers or mechanical moving parts that might freeze up if not used.preventing what might be described as "getting rusty" in the un-accessed areas .