Tino Best is passionate and gives 100% all the time, I agree. He is also one of the Worlds quickest bowlers, no doubt about it. However, he has never learned to swing the ball other than slightly into the right handers with the new ball. Otherwise it is gun barrel straight. His length is almost always too short. He has only improved slightly in all his years playing Tests and ODIs. He has also spent time with Yorkshire in county cricket and had a lot of time with Wayne Daniel. At the end of the day, the individual has to want to improve and be willing to change certain things if he needs to and Tino clearly isn't willing to do that.
Fidel Edwards has been a decent bowler considering the lack of support he had for much of his career. He was a bit hot and cold, either taking 5 wicket hauls or getting spanked, there wasn't much middle ground. At one point he was absolutely fearsome, regularly clocking between 150 and 155kph and even made it up to 157kph at one point. He does swing the ball too. However, he has lost a lot of pace over the last 18 months after another back injury and is no longer the same bowler. With his style of bowling, the pace was very important and without it he just isn't effective. He would have still been better than Best, Gabriel and Sammy, obviously, but we should be aiming higher than that!
As for the greats coaching our youngsters, I believe some of them are still having an impact. Obviously losing Maco was a huge blow and we have been robbed of so much knowledge and skill, but I know Curtly has been working very closely with Jason Holder over the last year and we have seen some very real improvements and elements of his relentless line and length have started to appear in Jason's game.