Is it permissible to place a copy of the Qur’an on top of another copy of the Qur’an, and is it permissible to place anything else on top of the Qur’an?

There is no impediment to placing one Mushaf (copy of the Qur'an) on top of another, as long as it does not lead to tearing or falling, for this is not considered a desecration. As for placing books of Islamic knowledge on top of the Mushaf, this should not be done, for the Hanafis have stipulated that the Mushaf should be placed above all books. If the item intended to be placed on the Mushaf is not a book of Islamic knowledge, then the prohibition is confirmed and reaches the level of impermissibility if it involves desecration, such as placing footwear, for scholars have stipulated the impermissibility of desecrating the Mushaf, based on His (Allah's) saying, "And whoever honors the symbols of Allah, indeed, it is from the piety of hearts."