Martyn. as to your last paragraph, you are correct, but only once airborne. obviously 1 pax 1 row forward is not a problem, but 70 pax all in the first 13 rows would be a big problem on take off, you would be operating with the stab trim already near the limits, thereby reducing your options incase of an emergency on take off.
In response to your first para, i was offered an interview with FR, but turned it down, as they charged £150 to interview me, plus £22000 for the 737-8NG type rating, at the the time i could not afford to get a job with FR….. Pilots have to pay for bottled water, food in flight, uniforms.. etc.. you get nothing for free. Although there starting pay is one of the worst in the business, but after about 3 years, they are the highest paying airline in Europe for pilots… if you can last 3 years.. a couple guys i know that fly with them were sleeping in there cars at the airport the night before there flights ( due to a strange rostering system where for so many days a month you have to base out of a different base from your home base, but get no extra pay for living allowance)