Projectile doesn't go towards crosshair's direction!

No. The other way around should be correct. You are at Position 20. You want to Position 100. 100 - 20 = 80. Normalize 80 and you get +1. You travel in the right direction. 20-100 = -80. Normalize that, you get -1. When you travel -1 from 20, you move away.

Edit: But yes, I meant “Initial Velocity in Local Space”. What happends in you just manually =* -1 the AimDir?