I find that I get much smoother cuts at high speeds on the saw, just because you have your speed control cranked up doesn't mean you have to cut faster, you are still in control of the feed rate, on long straight cuts I increase the feed rate then slow the feed rate down for curves and more delecate work.
The saws motor and linkages shouldn't come to any harm as it is designed to be used at the full range of speeds available from the speed controller.