I'm assuming this has been answered. but I haven't found anything in my research. I see some people have tried to create mods that offer transportation to and from TR and Vvardenfell. Is the general modding public also allowed to create other mods such as new towns, houses, dungeons, etc. on the new landmass? I know the TR team has been working very hard in creating this mod so I certainly don't want to impose by stepping on their vision, so to speak.

You are free to create any mod on TR you wish, provided you will not distribute their assets (however you can still use them since your mod will obviously be dependant on TR). Btw. there are some mods for TR, although some are outdated. Actual mods I know about are Graphic herbalism for TR, Poe Lighthouse (house mod) by Pluto and TR addons for scenic travels by abot.

Of course you can
TR even has a section on their own forum to discuss such mods.

Even if you don't want to make your mod on TR land, you can still use almost all the TR created assets in your mod. (consult the ReadMe to see which files are not open resources)

Just be aware that making a mod on TR is going to very likely require that you update your mod each time they release a new map. Since much of TR is still technically a beta and subject to change of its own.

Unless things have changed, you can use TR assests without a TR dependency.
(besides a few files that are "off-limits" )

Great to know. Thank you both. If I'm not mistaken, can't I use Morrowind Enchanted Editor to update my mod?