Re: Best engineering chief?
Geordi. He was a no-bullshit professional and a nice guy who worked well as a character without this emotional working class guy charisma of the other four chief engineers. When he had to take command of the ship he also did far better than Scotty or Tucker (I don't think that O'Brien or Torres were ever at the helm).
We saw Scotty in command of the Enterprise on numerous occasions. I think on the evidence we say he would have made a good Starship Captain.
On the continent of wild endeavour in the mountains of solace and solitude there stood the citadel of the time lords, the oldest and most mighty race in the universe looking down on the galaxies below sworn never to interfere only to watch.