Although there are rules covering how much weight you can drag and lift, I cannot find out a rule that dictates how much weight a creature can throw (eg, you grab a goblin and want to hurl it; the same with a chair or rock...) I do not mean treating the object as an improvised weapon, of course. Any suggestions?
There are no mechanics for throwing living creatures (well, outside of mythic anyway). As for throwing a dead creature or a chair, that would fall under the improvised weapons rules, so the GM would decide the properties of the weapon.