Not sure what causes the glitch, but I've started a new game with all items and all skills unlocked using the editor. I've also equipped my characters with the highest weapon in the game. I haven't been able to prevent the use of fast travel with what I've unlocked and I'm on chapter 3. Are you using the latest release of the save editor? I know a previous version of the editor had a bug where it could cause problems depending on what item was added, but it was fixed.
If you have the time and are able too it would be really nice if you could add different all categories like one for meds fish items etc etc and give an option for maybe 80 as well as 999. Since i'm pretty sure its adding some kind of unknown hidden adventure item form Dana's side that's causing the glitch. And i've noticed the editor really doesn't read addresses all that well since when i try to adds curtain items sometimes it adds them but most of the time it doesn't and also remove's important key items.