Is the mother's work halal in selling and installing radios, tape recorders, televisions, alarm systems, window tinting and graphics, speakers, amplifiers, and sound boosters, especially since the majority of customers are teenagers who use them to turn up music in America?

If the seller knows that this trade will be used for effeminacy, transvestism, and listening to singing and and music, then it is not permissible to sell it. However, if it can be used for permissible things, and the seller does not know the buyer's intention to use it for impermissible things, then there is no objection to selling it.