1. Wearing lipstick does not break your fast. 2. Kohl does not break the fast of men or women. 3. There is nothing wrong with using ointment to moisturize the lips or nose while fasting. 4. There is nothing wrong with applying creams to the body while fasting if there is a need for that.

Intercourse during the day in Ramadan is haram for men and women while intercourse during the night in Ramadan is allowed. For more, please see the detailed answer.

If you try hard to get rid of the blood that accompanies the saliva, then whatever is left of slight yellow traces in the saliva does not affect you and your fast is valid.

If the gastroscope is inserted into the stomach without introducing any other substances, then it does not break the fast, but if some greasy substance or anything else is introduced with it then it does invalidate the fast.