Kaffarah for breaking the fast of Ramadhaan

Q: I am a 26 years old unmarried Muslim man. In 2010 during the month of Ramadhaan, I had done serious foreplay activities with my past non Muslim girlfriend while I was fasting, and this happened many times which I don't exactly remember (probably 3 times).

Afterwards I regretted and for Kaffarah, I gave money (equivalent to feeding 180 people for breaking 3 fasts as per my calculation) to a mosque imaam who said that he would give that to an old and needy lady for her daughter's marriage.

Afterwards I got to know that first of all I have to fast for 60 days continuously. Even after this, I couldn't stop myself from sinning.

During Ramadhaan of 2017, I made several online foreign Muslim girlfriends (on facebook) and did obscene and nude video calls with them while fasting which also might have spoiled my fasts. After this, I did not offer a second kaffarah.

Now I deeply regret all of it and I'm very depressed. My family is now searching for pious Muslim woman for my marriage but I feel that I'm not sufficiently good. As I am working in a multinational company, it is difficult to fast continuously for 60 days without a break. I have good health but don't have the courage to do it (also because there are several lunch programs with colleagues and clients and it's difficult to refuse everytime).

Please give me the solution for this. If the first kaffarah (which I have already done as written above) is not accepted and I don't fast for 60 continuous days now, will I enter into kufr?

Visiting one's fiances house

Q: Is it against hayaa for a girl, who observes complete sharee purdah, to visit her fiance's house in his presence even if she intends to meet her mother in law, who is her father's big sister? If the girl feels shahwat in her heart and gets bad thoughts in her mind will it be permissible for her to visit her fiance's house? 

Giving sadaqah to one's poor sister

Q: Can I give sadaqah to one of my poor sisters. I have one married sister, she is a heart patient and needs to get medicines every month. Her husband is alive and works but the financial situation is very bad. Her one son is in boarding school and they often find it hard to deposit fees for him.

I decided to give 10% of my earning every month as sadaqah to them, is it permissible?

Salaah of a person who has urine drops problem and salaah time is about to expire

Q: A person has a urine problem, where if he goes to the toilet, for the next 30-45 minutes he cannot read salaah due to urine drops. If the time of salaah is about to end and the condition persists, does he have to make Wudu and perform salaah, or let the salaah become qadhaa and perform it after the time has expired. (The person is not a ma'zoor as the condition did not last for an entire salaah time)

Purchasing a property on an interest bearing loan

Q: My father bought an agricultural land almost 19 years ago, measuring 110 acres. My father is an advocate by profession and at the time of purchasing the land, my father had some money earned by himself and took some money in the shape of a loan from the bank and bought the land. I have heard that taking a loan is completely haraam, so is the land haraam for us? How do we make it halaal?