Here's my tuppence worth.
3. Seat pitch. That old chestnut. Most non ff pax have no idea about this, in fact many believe the pitch is set by the manufacturer, i.e "oh, if you fly on a boeing 737 you won't get much legroom". They don't know the seat pitch is set by each specific airline.
In addition, most non ff pax purchase an airline ticket ASSUMING no airline would be dumb enough to put seats so close together that it is impossible to sit in them. Unfortunately airlines can and do.
In regards to ff pax, just look at the success of premium economy classes or similar. People want a comfy seat, but do not really see a need for full business class. I personally just want a comfy seat with some legroom, I don't need champagne, priority boarding, enhanced meals, free alcoholic drinks etc.. Unfortunately, up until recently, the only choice has been cattle class or the super luxury of business class.
I happily choose airlines with larger legroom generally anyway, as firstly, it means there are fewer seats per given amount of space, which means that de-planing can be quicker, and there is more space in overhead lockers. Go on a charter with 28 inch pitch throughout, and you'll regularly find insufficient space overhead for even a modest amount of carry-on.
4. I agree. Sadly most pax can't easily access safety records, so they cannt make an INFORMED decision.
10. The clue is in the end of your question. I see no reason to pre-board a flight lasting eight hours in order to sit in my seat early (for 20 mins or more). In my experience, nowadays, airlines like to board pax early, so they can pull back from the gate on time (keeping their stats looking good), and then once the doors are closed, announce;"sadly ATC have changed our slot to approximately two hours from now, but we're hoping to leave earlier (yeah right!) so had you all board the aircraft now." That is exactly why ff pax don't board early. When I fly club, I never understand the notion of early boarding, to me it is common sense to stay out of the plane for as long as possible. Most ff pax learn from airline lies.
2. You know, when I'm on a really cramped econ short haul flight, I just chuckle when I hear crew say the main concern of the airline is our safety. If that were the case, we wouldn't have seats at wing exit rows, and we wouldn't be crammed in like sardines. Personally, I always watch the safety brief, and check the number of rows to exits in front and behind.
There is a more serious side to this, I've heard many people say this before. Many non ff pax believe if the plane is going down, then they'll all die anyway, and the safety brief is just to make people feel they will be safe, whereas in reality, they'll all be gonners. I know that isn't the case, and that somewhere between 70 and 80 percent survive aircrashes overall, but many folks do think that most people get killed in air crashes, regardless of the safety briefing.