Well, with your new driver it doesn't crash anymore, but nevertheless it's not working: the modules seem to be loaded but they are 'dead' - no display and no reaction to the keyboard.
I think the problem is, that all these "features' in the softwarelist are just not set when loading the module from the menu 'Media'.

The only idea to solve this problem may be to use your previous suggestion, i.e. to read these features only "if (image.loaded_through_softlist())", and else I would have to set these feature values directly in the driver, depending on the loaded module.
But for this I would have to know which module has just been loaded, so is there any function in MAME to get the name of the loaded module (in DEVICE_IMAGE_LOAD_MEMBER(ggm_state::cartridge))?