Is it permissible to buy a toy that contains objectionable elements that can be removed and avoided? And is the money paid for it or received for it lawful, or must it be given in charity?

A Muslim should utilize their time in a way that brings good to themselves and their Ummah. Permissible recreation is allowed in moderation, without excess. If the basis of the game is permissible and it contains violations that can be avoided by removing or concealing them, then there is no harm in purchasing it and playing it according to Sharia guidelines. There is also no harm in allowing others to play it. As for the money your brother gave you, if it is permissible to allow him to play, then there is no harm in taking the money in exchange for that.