I wouldn't recommend writing directly to the database unless you are very certain of what you are doing. And doing this sort of manipulation using wwsh for example would probably involve writing a lot of custom code.
Re: One problem missed from a problem setby Danny Glin - Number of replies: 0
It depends what you mean by objects. The data is stored in the database (in the [coursename]_problem_user table). It is retrieved by the WeBWorK code as an object, and then can be modified and written back to the database.