invalid condition

Making the condition that the husband cannot take a second wife

Q: I am planning to get married and proposed for a certain girl. The girl whom I want to marry said that if I accept the condition of not taking a second wife in the future, then she will marry me. Personally, I also do not want to take a second wife in the future. I want to spend my life with my first wife till I die. The question is: can we make the condition of not taking a second wife in the future at the time of the nikaah?

Which husband will a widow have in Jannah?

Q: I recently was asked to speak to a young man who wanted his mother to divorce her second husband. Whilst there were many valid reasons put forward as to why this divorce should go through, one statement was made which I do not fully comprehend. The son mentioned that when a woman re-marries, she will be in Jannah with the last man she was married to. Is this correct? In this case the woman was widowed as her husband was shot and killed in a robbery. The woman , no doubt , still has a lot of love and feeling for her late husband. They seem to be concerned about her ending up with her first husband in Jannah and hence justify the divorce from the second husband.Please advise.

Secondly, what is the Islamic viewpoint regarding making conditions on a person before nikah? For example, the woman will not fulfill conjugal rights or the woman will stay closer to her family instead of her in laws. Please advise.

Adding the condition "goods belong to the seller until paid for" in a sale

Q: Please advise on below:

1. Many companies state at the bottom of their invoice "goods remain the property of the above company until fully paid for" What is the status of the goods?

2. Is it amaanat or does ownership pass on to the purchaser? Is such a condition permissible?

3. Will the sale be faasid if such a condition is added?