I see; food plots, stump grinding, Christmas tree farm, and sawmill as the bullet points.
Food plots; IMO; 4,000# and 40 hp, is fine. Smaller works, bigger works, but thats kinda what im using as a guideline
Stump grinding, HST or Power shuttle are is not a requirement, dang near one, but HP, not that picky; stability, and rear remotes for side shift are wanted/needed
Christmas trees; 90% I assume that is mowing, but maybe a front auger would be nice? Mowing, HP is directly tied to size, which is dictated by spacing. Not knowing much, 10 ft rows between trees and 6 ft inline is what I saw. That says 7 or so ft bush hog to me; or about 45 hp
Sawmill; I see that as a max of 16 ft rounds; cleaned in the woods, and not transporting whole trees. Even still, these are often going to be 8 or 12 footers. So, honestly, 2000# max, but again, maneuverability is a big plus, on both ends; at the tree cut and at the mill, and then again stacking the cut lumber