RE: ZERO LIFT ANGLE
On Profili, click on the toolbar button for the polars, marked with a "P". Select your airfoil and the other settings and click draw. It will draw the CL vs CD polar. Then, a 2nd row of buttons appears at the toolbar. One says CL(alpha), CD(alpha). Click that and it will draw the lift and drag curves. Where the lift curve crosses the axis is the zero lift angle. See the pic: