Re: Bullet weight vs velocity
I would argue that it depends almost entirely on what you are asking the cartridge to do. For instance, if you are looking to hunt deer at ranges between 50 and 350 yards, speed and flat shooting might be your key criteria (little to no hold-over).
If you are setting up for elk at 1200 yards, you would want the most retained energy / highest bc/ most wind resistant bullet as possible.
Moose at 50-150 yds, you may look at heavy controlled expansion bullets with no consideration for bc.
I don't subscribe to the one-size fits all approach - there are enough options out there to let you pick what is best for your application.