Shirk

Someone asked if God can create a person and command us to worship him. My friend responded that Allah can do that because nothing is impossible for Him. Is this correct, or did my friend commit Shirk by saying that? Sayyed Mohammad Al-Musawi	Is is allowed to say Ya Hussain for Shifa without the intention of worship? Zaid Alsalami
I have been dealing with Waswasa and OCD for a while now. I get Shirk thoughts even during Ramadan though I don’t believe in them nor act on them. Do my fasts become invalid? And is there some cure for this condition? Sayyed Mohammad Al-Musawi	I heard a Shia scholar say that when prostrating at the doorstep of the Prophet (saw), with the intention of piety and love of Allah, this action is not regarded as an act of Shirk. Can you explain the boundaries of Tawheed and Shirk in Shia Islam? Sayyed Mohammad Al-Musawi