Has anyone made any modifications for this? Anything from new items, loot tables, or maybe even something that makes magic (ie: direct damage spells)more useful in the later game? I know it's possible and there are some good tools available to alter monster/NPC stats and edit items but I haven't found anything like a mod from searching around. Anyone know of anything like this?

I don't think anyone has made any mods for Wiz8. It would take some serious dedication to do this though.

As rift said, you need a lot of programs, advanced ones, and a heck of a lot of resources to pull that one off.

There is someone working on that kind of thing, has a full editor for Wiz-6 and -7, and a partially completed editor for -8, which can edit items, NPC's, loot drops and chests, and i think his plan is for a map editor as well, like he has in the 6 and 7 parts of the editor. There's some convo about this in the Ranged Parties thread, and a link to the editor.