What is the ruling on renting out three shops: one a women's clothing boutique (which includes Islamic and non-Islamic clothing and cosmetics), another a men's barbershop, and the third a women's salon (with no commitment to Islamic teachings in either of the latter two)?

It is impermissible to cooperate in what is forbidden. Therefore, if clothes are sold to those who display themselves immodestly before non-mahram men, then selling them is not allowed. However, if they are sold to a woman who adorns herself for her husband, then it is permissible. The rule is that consideration is given to the general condition of most people. If the predominant use of a commodity is in disobedience [to Allah], then selling it is forbidden. It is also forbidden to rent out a shop where haram items are sold, or where halal and haram are mixed. Shaving beards is forbidden, so it is not permissible to rent out a barbershop unless the tenant commits to Islamic regulations, including confining shaving to permissible hair, not imitating disbelievers, and avoiding Al-Qaza’ (shaving part of the head and leaving part). As for women's salons, it is not permissible to rent them out if most of the women are immodestly adorned, because that falls under aiding in disobedience. One must search for other activities that are far from acts of disobedience.