MacDaNife: any rotary tool will fail if its not taken care. Dremel/RTX will fail much earlier because the metal bits and dust may end in clogged in the motor.

always take short breaks to clean up the cutting area while allowing the tool to rest. clean the tool throughly after each usage so it wont have any clogged/build-up dirt/grime/dust in and around the body.

btw i think you left out other important stuff too: eye protection, ear protection, respiration mask. trust me, its more easier and accurate to work with when youve got all the protection. get a full covered goggles, i prefer slightly tinted black ones. it helps with all the sparks flying around. for the respiration mask, a single carbon filter element would do.