Harriers belong of different class. They are STOVL planes and and could not be replaced by non-STOVL planes. They would be retired with Vishal, and India is not planning any STOVL carrier in future.
Money is being wasted on N-LCA ,so that ADA could get experience in Carrier based Aircrafts ,so that they could make N-AMCA on time, rather than 20 years past it's utility.
It is extremely unlikely that India would piss off Russia, USA, and France at same time.Indian supply lines are secure.
And regarding three parameters you are talking about. LCA has American Engine. FYI, Engine of any fighter need to changed every 1500-5000 hours of flight depending on usage. That itself makes LCA dependent on USA, not to mention other foreign parts in LCA.