What is the ruling on owning a bag with a picture of "Big Ben," the Palace, and the adjacent church, and is that considered disbelief (kufr)?

It is not permissible to possess a bag with a picture of a church on it, as this promotes falsehood and symbols of disbelief. Especially since pictures of churches usually do not lack the image of the cross, and [the Prophet] "would not leave anything with crosses in his house without destroying it." As for clothes bearing symbols of disbelievers, there is a detailed explanation: 1. If they symbolize the religions of thevers, such as the cross and the like: It is not permissible to import them, sell them, or wear them. 2. If they symbolize the glorification of a disbeliever by bearing their picture or name: They are forbidden. 3. If they are permissible commercial brands that do not symbolize worship or the glorification of a person: There is no harm in them.

Mere imitation of disbelievers does not constitute apostasy that takes one out of the fold of Islam.