I've properly edited now and all looks great at char selection screen. However, when I go into world, the game crashes instantly as soon as the loading screen finishes, like 90% of the time. In some areas I can roam for a bit, then it crashes. It makes a weird glitch on the screen as well (attached pic).

I can confirm that the NPCs no longer have the HD models and they are back to the old ones, but judging from that glitch, I can see it's related to them.


EDIT:
Made a new char and had the chance to explore the NPCs a little more. There is something wrong with their model...to be more exact, the hair. CreatureDisplayInfoExtra.dbc needs some changes, or what could be the cause?

Below are some comparisons

I've done some tweaking, but I couldn't figure out how to avoid the crash when exiting the game. I want two things to resolve for this patch:

1. Avoid the crashes (spoils any change made in that session of the game)
2. Patch to affect only players, not NPCs

How can I avoid the crashes? Just remove the _HD from all lines, or there's something more to it?

Also, what files and their content do I need to edit in order for the models to be loaded only for players?

I couldn't find any DBC editor that can be user friendly, or have a proper search feature (so if you could pinpoint me to the right direction, that would be awesome).

Looking forward for your answers in order to jump in and tweak some more and get results this time.