hcurt.............

a lot of the things you've hit on are dependant on the particular gun. Barrel twist makes a big difference in bullet weight selection. Basically, the faster twisted a barrel is, the longer (heavier) the bullet needs to be to remain stabil in flight. You can compensate for shorter length somewhat by reducing the powder charge.........but that can become a negative thing for hunting if the load is reduced past a certain point.

Personally - in my 22" 1:28" twisted barrelled Knight........ I've found that my best results occur when using bullets of at least 300gr. For those 300gr bullets, 80gr of 777 works best; 350gr bullets like 90gr 777, and 400gr bullets like 100gr 777..
AS you can see - my loads tend to show the logical progression of weight vs powder. So I could probably shoot 200 or 250gr bullets just fine - as long as I reduced my load into the 60 to 70gr range..............great for target shooting........but NOT what I want for hunting.

Personal opinion here.................the reason for the light bullets & Magnum loads is for sales hype! That combination gives GREAT muzzle Velocity numbers...............but they never mention if they even hit the broad side of a barn with those Chrono'd results.

My loads give me 1" or less groups out to 100yds all day long and no animal has ever walked away after being hit once.................so this works for me.