- If i trade it away to another Civ, will the physical object still exist on my colony? Do i still get a bonus from it?
- What happens if i trade it away and then bulldoze it?
If you trade away the trade resource, the object on your colony still exists and gives the bonus levels to adjacent tiles. So yes.
If you trade it away, the other civ gets the trade resource for the specified number of turns. If you bulldoze the trade resource, the other civ still gets the goods regardless. You just end up with -1 of the trade resource, but there is no penalty for owning -1 of them.
Tested both of the above today.