1 - You don't need to do this action every tick, you need to do it at the start of the layout.
2 - This action is not necessary at all, because we determine the position of the crosshairs according to the angle using the formula.
3 - This action is not necessary at all, you fix the crosshairs at a certain point, but we must position it according to the formula every time according to the angle.
As for your question, you have not provided any information on how you have implemented weapon switching, how can we help you?