How were Native Americans perceived during 1750 to 1815 (American Revolution Years)?

Depends on the tribe. Some were very hostile, others were not. The Five "Civilized" Tribes were indigenous peoples of the Americas who lived in the Southeastern United States. Agriculture was the primary economic pursuit. The bulk of the tribes lived in towns (some covering hundreds of acres and populated with thousands of people). George Washington and Henry Knox pursued an agenda of cultural transformation in relation to Native Americans. The Cherokee and Choctaw tended, in turn, to adopt and appropriate certain cultural aspects of the federation of colonies. At the time of the Declaration of Independence, the culture of the United States as a nation was, itself, emergent. Many of the cultural practices appropriated by The Five Tribes were ones that they found useful.

You're talking about a period of 75 years, and different states and different tribes. Of course there were wildly different views and opinions. So there is no single answer to your question. On the whole though, most native nations were perceived as mere obstacles to be removed so that white people could take over their lands.

First Nation historian Big Chief Running Casino has written- Many Moons ago, the First Nation joined with the new immigrant white eyes from foreign lands to repulse the repulsive Red Coat invaders from foreign lands. It is written that with the tribes help, the Red Coats went home but we all pack heat in case they return. Check for our smoke signals.