What should a person, who doubts the validity of his Wudu, or over performs it, do?
One who doubts the validity of his/her Wudu while performing it should redo it until he/she is certain of having attained purity. But, if doubt was after having performed Wudu, then he/she should not pay attention to that as doubt after the end of an act of worship does not count. This is of course in case doubt was within the reasonable limits since once it goes beyond that, it becomes a whispering of the Shaytaan (devil) which he/she should ignore as the Wudu is valid.
Is permissible to buy/sell with non-Muslim?
Yes buying/selling for a Muslim with non-Muslim is permissible as regards what is lawful.
I went to the health center today to take an intramuscular injection of Neurorubin B12. The nurse told me that this type of injection breaks the fast because it nourishes the body. Is this true? I have heard that intramuscular injections do not break the fast, but I was unsure about this type, so I decided not to take the injection.
Therapeutic injections administered subcutaneously or intramuscularly do not invalidate the fast because they do not enter the digestive tract through an open passage. However, intravenous injections containing nutritional fluids do break the fast, as they are akin to food and drink in effect. The B12 injection is a therapeutic injection and does not break the fast. And Allah Knows Best.
Is abortion permissible when the family isn`t ready to receive a new baby?
Abortion is forbidden unless it constituted a serious threat against the mother`s life based on the opinion of trustful and God fearing physicians.