How should a Musaafir calculate if he has to perform full salaah or qasr salaah?

Q: How can I calculate 15 days during a journey in order to know whether I need to perform qasar Salaah or full salaah. Suppose I reach a destination on 1st Dec 05:30 pm and plan to stay till 15th Dec 05:30 am.

Do I need to to take into account till 15th Dec 5:30 pm (360 hrs) as it is less than 360 I should offer Qasr even though it is 15th day ?

Making a promise to fast if one's wish is fulfilled

Q: I had promised Allah Ta'ala that if He blesses my sister with a child when she was unable to conceive, I will keep 7 fasts for Him.

I even promised Allah Ta'ala to fast for two more reasons which He accepted and fullfilled.

I owe a total of 9 fasts for many years. I am trying but I am unable to do fast. Is there anything which I can do easily instead of keeping 9 fasts? I don't want to upset my Allah Ta'ala as He has done so much for me.

Making wudhu after sexual arousal

Q: I am a woman and suffer regular vaginal discharge. Sometimes after sexual arousal, I am certain that the discharge which is present is normal vaginal discharge because during arousal or sexual thoughts I didn't have any discharge nor there was climax nor any fulfillment nor any orgasm. Is wudhu sufficient to offer salaah?

Boy's father and uncles seeing the girl before the nikaah

Q: I am about to get married. My father, his elder brother, his elder sister and her husband are going to the bride’s house to see the bride and discuss the marriage. However my about to be wife is unwilling to uncover her face infront of them. What can be done to solve this dilemma because they all want to see the girl with whom their son is about to get married to.