I don´t know this webcam, but focus are generally mechanical. Maybe you need to disassemble and turn the lens, because webcams can´t focus too close.
For the ratio, you can change in "Settings/Webcam & Timelapse".
If you have development on these settings and are able to validate that they work, i would be interested to know. I have the same camera and i'm looking to do something similar. I want to fix the focus because the mechanical focus keeps adjusting when the y axis moves back and forth. Since my printer is printing for hundreds of hours, i'm worried that my camera will simply wear down and break soon.
That's making me think.... and i dont want to hijack the thread... does anyone know if the camera keeps working, filming, and especially focusing when no one is watching the feed or the time lapse is off?