Is removing a Facebook page created by the questioner, then owned by a friend, due to his posting pictures of veiled girls, considered haram or theft, and is it obligatory to compensate him by creating another page?

If you relinquish ownership of a page to your friend, it becomes his property, and your actions to delete or alter it are impermissible. Rather, you must repent and seek his forgiveness or compensate him. As for placing an uncovered image of a woman, it is not permissible. However, this does not permit you to delete the page, nor is it permissible for you to place images of women on the page. But if the page is still your property, there is no sin upon you in deleting it.