Is it ok to spend the night at London Luton Airport?

I'm flying in for a university interview to the UK this December and have not yet bought a plane ticket back to my home country. Ideally I would like to fly back to my home country on the same day as my interview finishes but that's not possible (don't wanna risk missing my flight). I now have two flight options,

one in the very early morning (6AM) of the day after the interview and
another in the evening of the day after the interview.

After my interview I plan on going to London or just staying where my interview took place. If I take option two (evening of the following day) then I will obviously have to book a hostel room for one day in London which will increase my finances even more (flight 2 is more expensive).

If I take option one I HOPE to avoid having to book a room and just spend my whole day in London and in the evening going to Luton airport to spend the night there. This plan is much cheaper so I'm leaning more towards it but I'm having some doubts about it:

is it safe to ride buses/trains in London at late hours (I plan on going from London to Luton at around 23:00 or something)?
is it immature of me not to book accommodation and to just expect to spend the night at the airport?

Lost my phone on South African plane

So, I was flying from one city of South Africa to another and fell asleep in the small plane. I put my iPhone away in the front pocket and fell asleep. When I woke up, I had forgotten about it and remembered an hour later when at my hotel. I tried tracking it with Find My IPhone, but unfortunately, it was on airplane mode since I was on the plane and wouldn't track. I'm coming back to the airport tomorrow to fly to another city, do you think they have a lost and found? If so, do you think my iPhone would be there? Like any other plane, I think the flight attendants would have checked all the pockets for trash and found my phone, right? Please answer, thank you!

Fear of flying, what can I do?

I have been really anxious about flying since I have a bad flight last year. The last flight I went on after I was shaking and panicking. It was embarrassing. My parents in law live a 4.5 hour flight away and have suggested we go over and see them, but we will get the flight there with them as they are over here anyway to help us with our baby at the airport. Not only am I scared about the flight but I'm worried that I'm going to panic and make a fool of myself in front of them! What can I do?

Added (1). Its not even so much the fear of crashing I'm worried about. Its because the flight was so turbulant and frightening I'm scared of experiencing turbulence like that again!

About bringing lots of whey protein boxes in check luggage through airline?

I'm gonna take an international flight from Canada to my asian country.
I see whey protein powder boxes are on sales cause of black friday so I want to buy more. But I'm worry about whether I can all boxes in my checked luggage(not carry on)? Am I allowed to do that?
And will the protein powder be metled during the flight?

Free wine on Air France flights?

I travel the same route quite often (Birmingham to Paris CDG) and as I usually travel with Ryanair/EasyJet was pleasantly surprised with my free sandwich and can of coke the first time I flew with Air France! Until my flight this evening where after asking for a coke, realised the man next to me had asked for wine (and it was free!) even In economy. Is this always the case for Air France even on short haul flights? Anyone know if it is time dependant? I'm taking a flight at 10am next week, but I might fancy an early drink or could even save it for later.