Dandilion: Use a color filter to guide the robot. Can use an IR led thing to emit lines to mark property lines. only need one linear actuator to disperse the weed killer. could have an average sized lawn done it about 1.5 hours max.
Clothes: Ehhh that would be tough considering there would be alot of strength needed in the robot.
Any other ideas?
Note: the robots will have a theft protection, so if it does get stolen, you'll just show them the id of the robot and they'll track it down and bada bing bada boom.