I believe the control surface direction circles will turn off if you turn off Feature Lines for those components.
However, you might not want to do that.
The axis triad at the nose of your aircraft might be a blank component -- you should be able to no-show that component.
The circles and triads can also be scaled (for a model in mm vs. ft. or m). Go to the View menu, Adjust... and then the 'Axis Marker Size' at the bottom of the menu. Make it very small.
Under the Window menu, you can turn off the global axis marker and the red border around the graphics window.
Under the Window menu, you can choose 'Screenshot...'. This will present a menu to use OpenVSP's built-in screenshot instead of the one provided by your operating system.
If you use OpenVSP's built-in screenshot, you can take transparent screenshots. You can also take screenshots at super-resolution (greater than on-screen) if you want super giant and high resolution files. You can also auto-crop the images tight to the model.
Rob