The law requires all ISPs to retain ‘connection data’ for one year. Connection data includes the source IP address, ie where you are connecting from, the destination address and port, which website you visited, how long for, and the amount of data transferred, but not the contents of the data as that would probably be encrypted anyway.
Now ISPs are allowed to retain this information indefinitely if they believe there is some commercial interest in it and they are not obliged to inform any one of this as it is commercially sensitive. But, storing it is expensive, so realistically they probably won’t want to keep, probably useless information for long anyway.
In answer to your other original questions, no you can’t request or demand that they delete information on ‘your’ use, in fact they wouldn’t obviously know it was you, all they can see is that a connection was made from the public IP address of the account holder, they won’t know which machine inside made the connection.
Similarly the answer to your third question is also no, they aren’t obliged to declare whether or not they share any data or with who.
Probably best to assume that every single intelligence agency in the world knows which web sites were visited by ‘someone’ in the house, and probably a number of marketing companies.
