Sea is too big. Hurling nukes at sea will only waste nukes. One needs precise an jamproof antiship missile to target ships. Second, I am talking of war scenario. India hardly has any reason to assume that Pakistan won't use nukes regardless of naval blockade and hence India will go for blockade
When was Indian aircraft carrier locked? Indian submarine as well as Pakistani submarines keep tailing ships and hence can be spotted at different times. This is normal course of cold war between India & Pakistan Refer to the cat & mouse game of USA-USSR cold war.
Any vessel that interferes in war will be attacked. So, India will warn Chinese or Saudi vessels to back off and attack if not heeded.
Which claims? I have mentioned DRDO chief's interiew about Kaveri engine being ready