the save game crash has been fixed. you were using an outdated version.
upgrade your eduke with the latest synthesis: http://dukeworld.duke4.net/eduke32/synthesis
your problem was very simple to resolve and you should have asked instead of giving up right away
as for using dosbox, you need to run the setup.exe that came with your duke game. it gives you the option to play user made maps. As far as mods and TCs go, most of them include instructions on how to install and run with the dos(4gw) -original- version of the game, so you need to read them then in most cases figure out dosbox commands (i.e. how to mount directories or simulate drives, browse through directories and list files, run programs with additional extended commands, etc.) to manually run their bat's or exe's - or write your own dosbox .conf files
Really depends on the TC you're trying to play. some are pretty simple to get going, some require a phd in rocketry or brain surgery to get running.
Thank you very much for the really helpfull tips. I will try the new synthesis...