Should nail polish be removed before making ablution?
Yes, it should be removed because it prevents water from reaching the nails.
Is Fajr (dawn) Sunnah a confirmed one?
All praise be to Allah The Lord of The Worlds Of course, it is a confirmed Sunna which the Prophet (PBUH) used to offer in a regular basis. And Allah Knows Best.
What is the expiation for breaking fast due to being on a journey, or being sick, or being in a state of menstruation?
No expiation is due on the aforesaid categories, but they are obliged to make up for the missed fast. However, if any of them failed to do so while being able to, and the next Ramadhaan has come, then making up for those days is incumbent on him/her , and paying the ransom as well. And Allah Knows Best.
I suffer from excessive gas, especially when I pray, and I redo my ablution more than seven times. I have obsessive thoughts about this matter, even though I went to a doctor and was given medication that did not help. What should I do?
If the release of gas stops at certain times between prayers, you should wait for that time, perform ablution, and pray. However, if it is continuous, you should perform ablution after the prayer time begins and pray, and the release of gas during the prayer is excused. And Allah The Almighty Knows Best.