Talaaq

Q: I am divorced with two children (boy 9, daughter 7). My ex wife, has as I am led to believe, settled down perhaps made or not made nikah with the man I accused her with whilst we were married. I am not sure but I assume he is also divorced, he too has two kids of his own, also a daughter and a son I think maybe a year older than each of mine.

My first question is: What is the most authentic ruling regarding custody of children post divorce? Where and with whom and from what age should they reside with either mum or dad purely from what Shariah explains?

My second question and this is what haunts me: If tomorrow they all decide to move in together and lets say they are indeed married for purposes of this question, how does the mahram thing work? This man, is he mahram for my daughter firstly. Secondly, his children being exposed to my children, I fear abuse, bullying, sexual abuse(possibly! as a parent this thought lingers as they grow older and left alone), and my children being teased by his kids - that they only in that home because my ex wife married their father. Tomorrow if these step brothers or sisters or whatever they will be termed, if their natural father purchases or does something for my kids , they could get jealous or nasty towards my kids, maaf but all of these scenarios seem to be playing out, hence my questions. 

Q: My husband wants me to take khula. My question is if I take khula will he take away all my gold ornaments which my parents gave and my dowry and furniture?

Q: In the state of anger and while fighting with my wife, I said "go to your father's house and dont show me your face ever". Though we were arguing and in the state of threat that Ill leave her etc etc, But didnt say divorce or anything. I had no intention to leave her. Let me know if it affects my nikkah? 

Q: Is it permissible for the husband to issue a talaaq while the wife is in her menses?

Q: I have a few questions regarding whether talaq takes place in these circumstances.

1. If a person says 'Recharge' or 'Macho' aloud with the intention of divorce, does this count.

2. I was uttering 'Salamu-alaykum' repeatedly with no intention. On the last time, when I reached 'alaykum' the thought and intention to divorce came to me. Does this take place?

Q: What is the ruling if a husband gives one divorce and gives the second divorce after 10 days of giving the first divorce ? Will it be counted as the second or not or the second divorce can only be given after the iddah period? 

Q: If someone don't remember how many talaaqs he gave, neither does his wife remember, then what is the shariat ruling for this?

Q: I give talaq three times in written form six years ago to my wife and before rukhsati. Now if I want to remarry that same girl what should I do?

Q: If I say to my wife just to threaten her that I have signed the divorce document and you will get them but i was lying. I haven't signed any documents. I was just trying to hurt her and threaten her. Will divorce fall? I have a clear intention that by saying this I didn't mean any divorce.

Q: I have just given birth 3 weeks ago and been staying with my parents. My husband and I got into an argument and in a state of extreme anger he said we were over. This was done over text message as well as verbally over the phone. He also sent a text message to my mum telling her also that me and him were over. The actual word of divorce was never spoken. Everyone is telling us we are now divorced. Is this correct?