Just got it out of the box

Q1: It has a 73mm bottom bracket - do I get the 68 BBSHD and do spacers/washers come with it? Q2: I have short legs and bad knees causing range of motion problems, the crank arms that come with the motor are standard 175mm I think - are there much much shorter cranks (85mm to 100mm) that I can buy? The bike industry thinks "short" means 160mm and that's a joke right? Because it's still way too long.