why PeaZip asks for password / may not browse the content of some archives?
PeaZip needs the user to provide the correct password to work on encypted archives. The person who created the archive is the only one to know it, and the only one that should be contacted to obtain the password. Current revisions of mainstream archive formats like (7Z, ARC, PEA, RAR, and ZIP) uses strong file encryption, and it is unlikely to be possible to brute-force it if the password is unknown or was forgotten.