[EricH]

David, there is another saying that applies as well as KISS.

"Keep it as simple as possible, but not simpler."

If, to meet your goals for a robot, a complex mechanism is required, simplify it as much as possible. Multi-speed drive? Use an off-the-shelf shifter, unless you also want multi-traction drive, in which case there may be more elegant ways to do both. Multi-joint arm? Is there a way that a single joint can do almost everything the multi-joint arm would need to?

Just a couple of ideas.