بسم الله الرحمن الرحيم
(1) Yes, you may wear it provided you do not consider the tawiz effective in itself and the tawiz does not carry any word of kufr and shirk. (Abu Dawud, Hadith No. 3893)
(2) It is lawful.
(3) You may take it provided you do not deceive people. However it is not good for the Ulama as well as respected people to take money in return of giving tawiz.
(4) No, it is not lawful to accept hadiya or take compensation after reading the prevalent maulud.
Allah knows Best!
Darul Uloom Deoband