Those women with whom nikaah is permissible

Q: I am a Muslim and 29 years old. I was an engineering student and during my bachelors education I used to teach Science Subjects to Intermediate co-education classes (11th and 12th Grades) in an Academy to meet my expenses as my father was suffering from financial crises. I used to control myself from developing feelings for the opposite gender and I succeeded nonetheless.

After 4 years of teaching, when I graduated from University, I found a better job and went outstation and I have been currently serving as a Senior Officer for 6 years.

When I got my job, my parents started searching for marriage proposals for me but they could not find a good proposal for 2.5 years. It has been 6 years since I left teaching.

The issue is that 2 years ago, I along with my class fellows had a get together in the University, and after having the meet up, when I was going back home, I saw one of my past female students (She was the sister of my my class fellow and I knew her even before teaching) in the University Library coming in front of me after so many years and her habit of keeping her gaze low and noble character forced me to develop feelings for her and I started to think about her as my wife.

After thorough thinking, I then sent my proposal through my family to her family and her family accepted my proposal whole heartedly because they already knew me.

My Question is that Is it allowed in Islam for me to marry her as she was one of my old students although at the time of teaching I did not have feelings for her in my heart and I am not teaching anymore? 

Q: Is it permissible to marry ones mother's brother's wife once he has passed away?

Q: Is it permissible to marry one's cousin (dad's brother's daughter) who is older then one by four years?

Q: I have committed zina many times and I am going to get married to the same girl with whom I have done zina, is it gunahand will I get punished for this?

Q: A is real mamoo of B. C is the male child of A and D is the female child of B. Is nikah between C and D permissible?

Q: I'd like to ask if it is halal to marry my aunties sister in law meaning (my aunties husbands sister).

Q: I know a girl and I like her but she is a sex worker and I have done a niyyat that I want to take her out of that so is it allowed in Islam to marry a girl who is a sex worker ?

Q: I got married 2 years ago to my wife who since then has been living at home. A lot of arguments had started between the family’s which then caused a lot of problems between me and my wife. 

2 years later she had applied for a Khula through the shariah council which they sent me a letter. I attended all the appointments in hope of reconciliation.

After the 3rd letter was sent out, she had issued a talaaq without my consent. 

Since then the qadhi (judge) told me she is in iddah and I could take her back and reconcile. The only problem I have was I don’t remember at all if I had said talaaq once in the past or twice with the intention to scare her and make her come to her senses. I need to know if the intention counts?

Also, during her iddah she had emailed the imaam and cancelled the talaaq that we have reconciled and doesn’t want to go through with the divorce. 

The same day the qadhi had emailed her saying talaaq has now been cancelled and we need to hand in our certificates. 

After a few days another argument arises and she tells me now after the 3 months iddah has ended where I was thinking I am still married that she told the imaam not to cancel it and carry on with the iddah

My question is am I still married to her as she cancelled it and then called the imaam to say don’t cancel it even though he said he has during the iddah me and my wife on many occasions had intercourse I am completely confused as in to f I am still married to her or not and so is she now and don’t k ow what to do

Please if I could have as much as information you can give me

Q: I'm really worried and need advice on the matter of first cousin marriages.

1. What is the Islamic view on the matter? Should I be worried about the research online which says the chances of having a kid born with some kind of disability increases with first cousin marriages.

2. Could you please give me famous examples, specifically of first cousin marriages in Islam. Did Nabi (sallallahu alaihi wasallam) marry his first cousin? Was Ali's (radhiyallahu anhu) marriage with Fatima his first cousin?

Q: I love a Muslim girl and wanted to marry her but she commited zina previously with someone else and she repented for that sin. Her argument is that she will only marry a zani male cause its written in the Quran. She can't find any Ayat and Hadees which mentions that the zaniya who repents can marry any muslim male.  So I want to know if you could please give me any ayat or hadees where it mention that a zaniya that repents can marry any muslim male.