Good for you, taking on brands like Husqvarna and Robomow and Lawnbott and all the rest! There are zillions of people with lawns, and if you can make a dent there, you have a real business!
I think that a PCB with 12 active cooling fans looks a little weird. Fans fail. 12 fans fail 12 times as fast (well, at least one of them will.)
I'm curious: What are you doing that can't be solved with a passive aluminum heat sink? And, if you need active cooling, why not a heat sink/pipe/fins with a single fan, like robust solutions from everywhere else do? This is an honest question; I may be totally missing something.
On presentation: Quoting the 3 laws of robotics is cute and all, but personally I just rolled my eyes when I saw that... Yes, having proximity sensors is great! But the "3 laws of robotics" are neither laws, nor robotics, IMO, and don't define "what makes a robot." If it helps you fund the kickstarter, then maybe it's all good anyway :-)
Also, have you considered talking up the environmental benefits? Electric drive means no exhaust, no gasoline/oil, no feeding unstable parts of the world, and no CO2/tailpipe emissions from your lawn care. Early adopters of products like this probably skew more aware of "green issues" (says me, without asking any marketing consultants...)