For some years in the UK publishers have been asked to sign the Publishers Record Card - on which the hours etc are recorded. I recall this is done once every few years and is deemed to give authority for some years.
This gives the cong the right to hold the cards for years in storage.
Re Judicial records - no notes or letters should be stored at the cong or indeed made during JC procedures. The cards sent to the society (in a Blue Envelope) by a cong to report a DF list only the cong name, persons name and scriptural reasons for the action. -
Congs get a card back stamped by the WT and this is kept in the cong confidential files and should be reviewed annually in September when elders are supposed to consider visiting DF ones to help them (as a WT article directed some years ago)
Congs also keep a Special Shepherding list which shows any issues re child abuse - listing the names date and little else. All correspondence in such cases is sent to the branch and no copies are allowed to be kept.
Branches will also have (and congs a copy) of the S2 form re appointing / deleting MS & Elders and this may have just general comments re the individual - nothing exciting really
Congs are independent of the Branch as far as the charity commission is concerned and should not pass on "personal details" - but this is unlikely to happen .
Details will also be kept re name address status ets by Regional Building Committees and other similar offshoots.
Oddly I still receive mail re KH Electricity / Old People homes for JWs etc - which must come from some mailing list somewhere but it is years out of date as I was PO years ago.
COs do report on individuals with "special potential" on something called a Personal Qualifications Report PQR - only likely to apply to zealous young pioneer/managers