landing is where both, the plane and pilot is tested.
take off can be done with faulty instruments...
yes. There are lots of young pilots available who have the required experience. Not only that, flying is stressful, I cannot imagine how a 64 year old would cope with all that...doesnt sound good.
when it comes to being a pilot, a good character and etc is not whats crucial to the safety of the passengers, its his experience at number 1 and health at number 2. Experience can never compensate for poor health.
Although his health was probably not the problem here.