looks reproducible, strange i cannot catch anything like those deadend software failures, but maybe our with matthey set of kickstart modules differ from yours.
regarding final computer freeze, do you have any outline fonts, because it doesnt seem like that, can you install any, or alternatively use fixed fonts option in your choices file as chris posted above?
edit: to reiterate you need to edit your choices file to contain:
use_diskfont:1
font_sans:helvetica
font_serif:times
font_mono:topaz
font_cursive:garnet
font_fantasy:emerald
the choices file is somewhere in afair netsurf/uses/administrator, or so (i cant check just now)
edit2:
also for future testing you should be able to redirect the debug output either to a file or to serial, in later case you can catch it via null modem + (alternatively) usb adapter on terminal program on another machine.
the instructions how to do that are likely here:
http://www.amiga.org/forums/showthread.php?t=68782