Yeah I'm 6'0 200lbs- My hobbit will rip up the steepest hill in town. I thought it was quick with me on it- then my 165lb brother-in-law hopped on it and was doing 50mph in 2 blocks lol.
I doubt you'll bend a hobbit rear axle. It's no wimpy 10 or 12mm shaft- more likely to bend the rim. And you'll need better shocks and bigger springs under the seat tho- I bottom mine out pretty easily.