1. Is a father allowed to give all of his maaser money to his son learning in kollel?
2. I need some help in formulating a shtar that will enable some mechalalei Shabbat to do at least a shetar mechira of their business.
1. The Gemora (Eruvin 63) says that one should not give all of one’s tzeddaka money to one person. Rav Cahim Kanievski advises not to give more than half of one’s money to close relatives. See also Iggros Moshe (Y.D. vol. 1, siman 14) who writes that one may give the majority of one’s tzeddaka money to realtives and the rest one should distribute to other worthy causes.
Furthermore, if the father had obliged himself in advance to support his son, he cannot pay off this debt with ma’aser money.
2. The Shtar is complicated to draft and depends on many variables. It would be best to contact the Beis Hora’ah by phone.