Looks like a neat lifter system, what is the MOD on the gears?

As far as working to the limits, I try to think of it like this - if I don't test my robot at the extremes of its operation, it is more likely to break in the arena when I really need it to work. If something breaks now, it isn't as big of a deal because it is in a controlled environment and you'll know about it, either to adapt around that limitation or make it more reliable for when you really need it.