"Leaches needed and Iron sword to reliably hit or a bronze agitar."
No, leaches need a spear. Even a flint one is better, thou fang easily oneshots them.

Havent seen difference in pickaxe "damage to ground" but usually the best tool if you are going to do a lot of landscaping could be antlers. Easily repairable (workbench) and the least stamina usage. So Bronze vs Iron is probably the same, stamina difference.

Similar with Axes, Bronze axe is the best one for chopping wood. Period. (with random exceptions baded around skill levels).