Er...just make sure you are really, really careful with this as you are violating copywrite/copywrite infringement. I doubt anyone on the site would tattle on you, but I did want to warn you nevertheless.
Also, creating a text adventure with an open world aspect and RPG elements is going to take you more than a couple of months even working on it every single day. You'll need A LOT of dedication to the project; not to mention writing and coding EVERYTHING involved with a game that large and all the areas, NPCs, Quests, etc. If you've never worked on a game like this before with Quest, I suggest starting on a much, much, much smaller scale and then moving to a large scale game once you have all the coding and technical elements down. Just a friendly suggestion :)
I looked deeper into gaming copyright law as you suggested and found you were indeed correct. I will be scrapping this idea. The last thing i want to do is get in trouble with the admins here at textadventures.co.uk...
however i will definitely be making an open world fantasy adventure game soon.
I know these things take a long time, i was saying some people could "beta test" the alduin arc before i releasef it, wich i now wont be doing.
You can always make a TES-like-RPG of your own (totally original/yours - create your own RPG world and history, races and etc, as TES did for its games, so no legal issues)... but it's still an extremely ambitious project/endeavor... I've been trying to work on one myself (though still trying to learn to code and design better), though I'm still just working on character creation... and brain storming game design. If interested we can try to work together, if you're still interested in making a TES-like-RPG game (as that is what I'm trying to do too/myself)
here's some of the game design brainstorming/ideas I've done so far:
(tried to put them all into this one place)