Addressing your second point:  The unification of the islands by Kamehameha can be likened to a 'civil war' in that it was internal throughout the islands without the influence of outside countries.  The King then went on to institute a constitution in 1840 and was internationally recognized as independent nation Nov 28, 1843 with the Anglo-Franco Proclamation
The United States, however, landed the marines on the soil of a recognized independent country who was at that time in the state of peace.  Those actions were an illegal act of war as was later referred to by both Heads of State (Queen Liliuokalani and President Cleveland) in their written correspondence in 1893.  Those same words 'an illegal act of war' was repeated by President Clinton in 1993 in Public Act 103-50.  It is also a fact that the Kingdom of Hawai'i was never extinguished which is a requirement under international law.  The illegal war still continues until today.  The Hawaiian Kingdom also still exists today.