There's 1 year cliff for vesting but apparently one can excercise at the current strike price on day one and that's pretty common among other startups with folks who want to avoid the AMT
I agree with some parts of your answer but I have always wondered do u really evaluate the capabilities solely on an ability to solve these mind bending problems, there are lot of folks who might not know how to get an exact solution for a crazy hard dp problem but are very good devs and vice versa is also true a good cs interview might not necessarily translate to a great dev in a real world scenario.
I will hold off until then.