I often drew lines in the ground with my toe and asked people not to step over them until I was done. If you leave a camera on a tripod unattended, it will be knocked over within seconds. Always stay within rescuing distance. This allows the other person to wander around unobtrusively and film. If you don't do something like this you will end up with hours of footage of people staring into the camera.
Midday lighting in the tropics is very hard for the best of cameras to deal with.
Use a polarizer, a neutral density filter, and consider filming when the sun is a little more friendly. Keep that other eye open. Don't ever be so involved in your viewfinder that you don't see something coming at you from the side. I'd thought it woild be impossible to shoot a documentary without someone along to help me film, but I was wrong. The camera gradually became a part of my life and I learned to see the world through its lens.