I walked over there and there's three new NPCs that all look the same and their names (when you hold the cursor over them) reads as dialouge. When I talk to them they say something like 'I don't want to talk to you, stranger; why would I want to talk to someone that barged into my apartment,' or something along those lines. Plus, there is a formatting error in the text box - some of the text is grouped all on the right side of the screen. What's the deal?

-thanks.

It looks like some sort of incompatibility or corrupted installation of mods/game.

Please post the contents of your WeiDU.log and the name of any non-WeiDU mods you have installed.

I only had one other mod installed before this one and it's the mini quest pack. I tried uninstalling both and then reinstalling grey clan only but it still won't work. Maybe it's because my save game still contains the old data from the original installs. For instance, a scene from the mini quest pack was still present after uninstall. To be honest with you, I've had the worst luck with installing mods!!!!! For instance, I installed only one mod for BG2, and it was a very popular one, and it caused the game to not load. That forced me to reinstall everything for stratch.

Old savegames must be used with care. There are several possible scenarious when they cause problems with mods (for example, certain files are stored in the savegame and mods don't update them). However, it occurs more often that an overwritten dialog.tlk is responsible for the problems.

Reinstall the game (and delete any remaining files in its folder after the uninstallation), or at least, start a new game. The first one should solve all problems (provided you don't make the same mistake in your mod installation order/setup again -- assuming that is the problem now), while the second one should be sufficient to sort out your problem regarding the Grey Clan Episode I.

Have you installed the official BioWare Patch v5512?
This patch is required.
Your installation should looks like:

BG1 + Add-On
BioWare Patch v5512
Grey Clan Episode 1

Greetings Leomar

The line is from BGQE, yes. If you have mixed-up text lines and names, it is mostly a sign of an old save-game used with new mods installed in a different order. Starting a new game should do the trick.
But I would like to ask: Which scene of BGQE is still present after deinstallation (in an old save game)? If you mean a character that spawned before, then it is logical, as it is saved in the save game. (He shouldn't have any dialogue if clicked on, though. Not very convenient, but nothing I could do anything about it.)

I "successfully" played with both BGQE and TGC installed (I say "successfully" because my run was bugless but I needed to ctrl-y my way through TGC, thanks to the wonderfully balanced encounters), so they aren't incompatible.

A character saying lines from another mod is a clear sign you need to restore a 'clean game' backup (or fully uninstall the game and reinstall) and then reinstall the mods, making sure you aren't running both installers at the same time or running them while the game is running or something similar. Starting a new game without reinstalling isn't going to help in the least.