Hmm looks like your using blender that's very promising!
I'd love to see a easy way to import/export files to and from blender to create s3d zones and objects between that and GIMP it's pretty much all the open source tools needed to do all 3D related customization content design stuff.
On the subject issue of private servers here's a interesting tweet comment I had made awhile back on twitter "@Aradune Interesting...to be getting endorsed support from private servers, but honestly its exactly the exposure you want @RichardGarriott"
Here's a tweet I got back in return from @RichardGarriott and for some clarification @Aradune is Brad McQuaid a key designer of EQ.
"@BinaryPimpSmack @Aradune While obviously we must protect our own bottom line & trademarks, private servers allow important self expression."
If so, what's to stop me from making and distributing a program which modifies peoples' files for them in a pre-set way, e.g. inserting new textures into an .s3d and modifying a .wld, but not distributing any of the original data from those files?
If you aren't distributing any original data then that's legal as far as I can interpret at least. Creating a program isn't illegal. As a example using a hack might be illegal depending on what's being done with it, but creating one isn't.
http://www.project1999.com/forums/sh...ad.php?t=87281
Over at p1999 by Nilbog has a program that somewhat does what you say to fix some transparencies glitches within the early game and had this to say.
Is this legal?
Yes. This includes no copyrighted files. It simply modifies your existing files.
Based on Nilbog's claims and even from @RichardGarriott's response in regard to private servers I'd interpret that as yes it's legal. You aren't distributing anything you don't own and it's a important form of self expression a fundamental freedom of expression protected in the constitution your able to express it fully within the rules of the laws of it.