Nikaah & Marriage Issues

Q: My question is regarding maintenance. My husband and I have two daughters and a son that is four months old. My husband's ex wife has dragged him to court for maintenance numerous times and he has told the court he can not afford that which she is asking but can pay a lesser amount. The councillor in charge of his case has now told him to get a better job and that I should find a job to so that I can support our children and he must then support his previous child. I need to know what Shari'ah says regarding the fact that my husband must solely see to that child and not the children he has with me. His ex-wife has also on numerous occasions told him why did he have another baby when he can't support her daughter. And that her daughter was there first so she deserves everything. I'm quite shocked and hurt that she would be so towards my kids when we don't ask her for anything. She is married to a sheik and is in purdah but belittles my children when ever they appear in court.

Q: Is it better to mention the full name of a newly convert non Muslim in his nikaah in the audience even though he has got a non Muslim surname (family name) or one just has to mention his normal Muslim name (Yusuf or Ahmad etc) and leave out his surname?

Q: Would a father be sinful for giving some of his children more money than others - for example financing the trip of one child to go abroad but not giving any money to the other child? Another situation might be the father giving one child thousands of pounds for their studies and giving nothing to the other child. Or does Shari'ah allow a father to give one of his children more money than others (whilst the father is still well and alive)?

Q: If one is on a very high dosage of medication which would cause total abnormalities to an unborn child, and if that person finds out that they are pregnant, can they abort the child in the early stages? Birth defects and abnormalities are extremely high.

Q: Is there anything wrong with having an invitation from the girl's side at the time of her marriage, which is in addition to walima (on the assumption that at such a function there is a guarantee that there will not be intermingling, wastage, music, extravagance etc)?

Q: Is family planning allowed only by manual orgasm?

Q: I would like to know if you have given one talaaq and the iddat period has passed, can the man and woman still reconcile and if so what must they do?

Q: I married a Christian girl and conducted the Nikah myself - i.e. I got two non-Muslim witnesses, asked her if she accepted my proposal based on the Mahr I gave her, she accepted and I then read the Nikah Khutbah, and confirmed that I have accepted her as well in my Nikaah. First Question: Is my Nikaah Valid? Secondly - things did not work out and I have subsequently given her 3 Talaaqs telling her that I divorce her in front of two Muslim male witnesses. If she reverts from Christianity - can I remarry her (perform Nikah again) or not? (Does she first need to remarry someone else etc.)

Q: Is there any dua to recite before having intercourse?

Q: After marriage what dua should be recited in the ear of the bride and is it important?