I don't know if anyone has done anything with mods for Quake DS, but with the help of Simon I finally managed to get Rocket Arena working. I also included custom maps that are low on poly count to help increase the game's speed.
You can play Rocket Arena from the non-wifi version of Quake DS, and it comes it two flavors, Rocket Arena and Deathmatch.
The Bots are powered by Mr.Elusive's Omicron Bots, which learn the maps and your pathing to make them very competitive. There's a set number of random bots with their own skin and abiilties. You can add and remove bots until you find one with the challenge level you are comfortable with.
A full version fo Quake is required, as well as using PakExplorer to modify your PAK0.PAK file to run this mod. Without a commandline, there's no other way possible. You're simply overwriting files, and adding new files that the mod needs. I cannot distribute the PAK file premade, but I can provide the files you can add to your own.
I'm waiting on an reply from Simon Hall before I release these PAK file additions, but in the meantime, here's a pic and youtube: