Hmm I see, I've actually asked a few others and they all said if it's already subjected to withholdings, then there's no need to file a return. A statement in the tax form also states that: "However, no return is required to be filed by a nonresident alien individual, nonresident alien fiduciary, or foreign corporation if...the tax liability of such person was fully satisfied by the withholding of U.S. tax at the source."

So, I assumed I don't have to file a return, but seems like I should do a little digging first. I appreciate your help again though. I wish you all the best :))