Is it true with new rules in mind,that if a fig throws an object at enemy fig and regardless of whether or not it hits, the object becomes rubble(hindering terrain) instead of being removed from board completely?

No. Objects are removed from the game when used as weapons. If an object is destroyed by an attack against the object, you place a rubble token in its place.

Thanks Psylockeslover. That's what I thought,but I read in someones post in the strategy and tactics forum that it was true.

What if you use TK to target an adjacent stealthed enemy fig that also has the object in his space? I mean using that object,that's in same space as the enemy fig,to target him with. Would object become hindering terrain or would it be removed from board completely?