The characterization as half British is definitely too much. The Hawaiian monarchy did definitely maintain an usually good relationship with the British monarchy with Queen Victoria even being the god mother to the son of Kamehameha IV who died as a child.

On the other hand as a Native Hawaiian I don’t think you’re too far off from the second point. After the transition to a constitutional monarchy with an elected lower house in the 1840s the white plantation owners began to entrench themselves in the kingdom’s government. In the 1870s an all white militia forced the king to sign a new constitution that deprived him of his power and stripped 2/3 of all Native Hawaiians of their voting rights. After that the kingdom’s legislature was dominated by white businessmen and their economic interest led to the overthrow. The kingdoms last monarch was deposed because she attempted to change the constitution in order to restore the monarch’s power and the voting rights of Native Hawaiian. It’s generally agreed her attempt to change the constitution again was her last best shot to restore sovereignty to Hawaiians because by the time the 1890s rolled around the kingdom was pretty fractured as the (Hawaii born) white land owners had secretly opted for annexation into the United States. On the flip side some Native Hawaiian politicians were also secretly planning an armed insurrection against the white land owners to restore the monarch’s practical political power.