I agree, but not only did they refused to bring in external people, but they also don't learn from their competitor's products. At the end of the 2014 season McLaren send Honda their spare Mercedes engine.
Alonso's problem is the amount of enemies he's made with his conduct. He can never go back to Ferrari. Both Vettel and Ferrari really don't like him. Renault GP is his only realistic option.
I think Mercedes is clearly better than Ferrari. The difference is not as big as it used to be, but still Mercedes can win every qualifying with ease and they only struggle with the race on a few circuits where it's extremely hot.