QA-INT-1: My disc was stuck in a tree far above two meters (with the two-meter rule in effect), when another player’s throw knocked it to the ground. Where is my lie, and am I subject to a two-meter penalty throw?

The interference rules state that a disc that has been moved is played relative to where it first came to rest. Since that was clearly above two meters, you are subject to a penalty throw just as if the disc had stayed in the tree.