Good post!
As a flight attendant myself, ill add a couple of things.. You are right that the back tends to be emptier, this is not only because people prefer to sit at the front but by defect the check in agents push people to the front for weight management of the aircraft. Also on ULR (ultra long range) flights, normally the crew have a Crew rest compartment at the very back of the aircraft so around this section no babies are allowed to be seated so they don't interrupt the crew's rest so you can ensure you won't be stuck next to a crying baby! The only bad points of sitting at the back is that you will feel any turbulence a lot more and sometimes when the airline runs out of your meal choice the last customers will have to take whatever is left.
Staying hydrated as you say is very important as we dehydrate a lot more up in the air, try to avoid tea and coffee as these will dehydrate even more. For example on my airline we are no allowed to give out big bottles of water but if you bring your own empty bottle we are more than happy to fill it up for you, this saving us the hassle of bringing you a glass every half hour and also saving a bit of plastic!
Being friendly to the crew is always a good idea, all crew will go that extra mile if you really ask nicely and just give a smile with a please and thank you, if you walk around as if you are entitled to everything you will get no more than what you really are entitled to, we can bend a couple of rules for people who deserve it!
All other points I agree with but then depend on the airline, we provide snacks, blankets, and hundreds of movies so sometimes its worth paying a little extra for making that trip easier.
Keep up the posts!
RE: 10 TIPS ON HOW TO SURVIVE A LONG FLIGHT