Could the Imams hears us and see us? Could Imam Zaman (may God hasten his reappearance) actually see us and hear if we talk to him? Or say Salam or Good Morning? Could they see what everyone is doing? I heard someone say this before but I thought only God could see and hear us all only.

Yes they can hear us because Allah has empowered them to hear us. When we speak to them, Allah delivers our voice to them. So they can hear us by the permission of Allah.