Sehri and Iftaar

Q: As I am fasting I thought the last time for sehri was 3:50am (mistakenly) but the actual last time for sehri was 3:49am. I drank water at 3:50am sharp. Would my fast be valid?

Q: My question is regarding the upcoming Ramadhaan.

I am a young married man of 33 years. I have no disease, Alhamdulillah, no limitations that I can postpone or quit my fast. I have been fasting for many years also. I have lived and experienced some normal 9 to 15 hours fast in Pakistan maximum and then in Dubai for 3 years with the same timings of fast. Now I have moved to Oslo, Norway. This Ramaadan will be my first here In Sha Allah.

As you know, Norway is among the country where sunrise and sunset is very long. This would be almost a 21 hour fast, which I feel is too long and the time for iftaar and sehri is too short, that I cannot make or feel the pleasure of iftaar, sehri and Taraweeh. In Oslo, iftaar will be around 11.30 pm and sehri will be at 2.00 am.

I feel that we must give proper time to iftaar and sehri as the fasting body needs it. I am thinking of fasting according to Saudia or a country nearby with normal time hours of fast. Can a person do this? Is there any Fatwa for this? As I do not know any other doing like this here in Oslo or not... and I am also thinking of offering Isha and Taraweeh at normal hours, which would be normal Asar or other time of Salah time here in Oslo in the Month of Ramadhaan.

Q: Is it obligatory to floss after eating when a person is fasting? Sometimes food can get stuck and I can't feel it there.

Q: I’m fasting. I try to follow the most accurate sunset times. Of course these different sites and apps make estimates of what sunset time is. For e.g, today one would said sunset is at 3:53, another two said 3:54 and another site said 3:55. I naturally would follow the latest one as a precaution, but nevertheless, would it be permissible to follow the earliest time?

Q: I woke up this morning and drank water after fajr. Not realizing I needed to fast today. However, since then I haven't eaten or drank and want to keep my fast. Would it be accepted? I didn't know I had to fast today and a friend told me. 

Q: If I keep my qaza fasts and nafl fasts without eating sehri, will the reward be less?

Q: How we can decide when it's the right time to stop sehri?

Q: What if one breaks the niyah of روزہ قضا after azan of fajr because he wasnt able to wake up for suhoor. 

Q: If a person thought the athaan went off while fasting in Ramadhaan (he heard the athaan on the radio or someone gave the athaan as a prank) and he broke his fast is the fast valid?

Q: Sehri time till is 04:03am but I not knowing ended my sehri at 04:10am. Later I found the correct time. Is my roza valid?