For #2, Rhidian's code should work if you register that trigger for both players and items (two separate functions).
I think #3 could work if you had a character with a set path. You'd have to set the tracking markers on the path of the character manually and then set them offstage. When you use the ability on the character, you'd put the markers you placed on stage.
If the character doesn't have a set path (e.g., is on a wander script), then I have no idea how you'd do it.
Skill #3 is supposed to be a lot less complicated than that, the character you check up on can be stationary throughought the whole game but i'll just put some breadcrumbs or something where he's been previously, without having physically moved there in the actual mod.
