How to import miniDV videos without iMovie over USB?
It's most likely that the support that was built into macOS (OS X 10.1 through 10.3) is no longer available in current versions of macOS.  From the PV-GS35 User Manual (page 45): 


  
  For Macintosh  OS:  Mac OS X v 10.1 – X v 10.3  CPU: iMac, iBook or Power Book G4, Power Mac G4 or Power Mac G5  RAM:
   64 MB or more
  The USB equipment operates with the driver installed as standard in OS.
  


The driver is obviously obsolete given that the only listed support is for PPC based Macs. It's a very good bet you're not going to find driver support for Intel based machines.

Unfortunately, this device doesn't show up as a camera and you will need software to not only extract the images/movies, but to control the camera as well.  I ran into this very same problem with a Sony camcorder and the only way I was able pull the videos off the camcorder via USB (to ensure the highest quality) was to light up a Windows computer, install the software and extract my videos.    The other option is to use a video capture device and get it via the analog input/outputs.