I know some may feel it's a silly question, but let me ask it anyway

I am planning to travel from New York's JFK to Gatwick, London.

There are 2 choices: Norwegian Air Shuttle and British Airways. BA is more expensive even if you include the free food and the other goodies.

But, focusing just on the safety aspect and nothing else:
1) British Airways has 7/7 safety rating, clearly has a very large fleet has been accident free for way over 20 years. Norwegian's is 5/7.
2) British flies much older planes - B777-200. Those flying this route are over 20 years old.
3) Norwegian flies Dreamliners (B787) - new, composite planes. I read that are not just lighter, but potentially much more reliable and safer because they use electric motors instead of the pneumatic mechanisms all over.
4) But when it comes to pilots and their experience British Airways is definitely way ahead - Norwegian aggressively hires new pilots, according to many reports, pays them less and hires them on contractual basis, taking advantage of registration in several countries. Most likely they are much less experienced than the BA pilots, and I bet BA's maintenance and safety processes are much more robust and have existed for dozens of years.
5) B777 in spite of being quite old has one of the best safety records of any airliner.
6) Norwegian definitely stresses its planes more. They have to, because they don't have Business and First Class so their revenue is much lower than BA's per plane/mile.

Having all the above in mind, would you choose BA if you cared about safety as your one and main priority (forgetting comfort, entertainment, etc.)?

The price difference for some dates in the fall is 200 to 300 dollars per round trip ticket.