I looked it up a couple years ago, and my chance of dying for any reason at my age was around 1 in 7000 each day, and that's just from waking up. The chance from dying for a professional tree worker was around 1 in 300,000, so my part-time little job stuff really doesn't increase my chance of dying very much. The benefits probably outweigh the risks. A tree work accident is a just one more item on the long list of things that could put me in really bad shape at my age.
I don't even think about being taken advantage of. How can you take advantage of someone who is lucky enough to be able to do what I do at my age just for fun and satisfaction? Just can't happen. The advantage is all mine.