Hey guys
Can I move a heavy special object with TK into a square that is occupied by a character?

So long as an Object is not Immobile, or doesn't otherwise specify that it cannot be placed, you should be able to target and place it with Telekinesis.

A Character or other objects in the target square do not prevent placing an object in that square.

yes.

If the character is a friendly, it's not an attack, and that character may now interact with the object (i.e., pick it up and use it in an attack, etc).

If the character is not a friendly, then this is an attack.

Nothing in the PAC about TK specifies that the targeted square must be empty of characters.

(You've discovered the Bat Signal, I presume?)

It can be an attack, but you are not forced to make an attack. You are free to just place an object under an opposing character.

Thanks a lot guys