I appreciate you're probably sick of hearing this, but I cannot get the mod to load
If anything does load, it's the default BtS screen, from which I have the option of playing a standard BtS game (i.e. like I would w/o a mod loaded)
No scenarios, no mod. Zilch
Help please?

I have downloaded the latest patch (1.20), have BtS on the most up-to-date patch version; I'm running on Windows Vista
I've installed the full install to C:\Program Files\Firaxis Games\Sid Meier's Civilization 4\Beyond the Sword\Mods; the "Sounds" folder to C:\Users\<insert my name here>\Documents\My Games\Beyond the Sword\CustomAssets\sounds; the scenarios are both inside the full mod folder and in C:\Program Files\Firaxis Games\Sid Meier's Civilization 4\Beyond the Sword\Mods, and I have merged the patch files into the scenarios folders

Have attached errors I get when trying to run main mod; any help would be appreciated

Check where it's installed to see if there's a Star Trek folder inside the Star Trek folder. If there is, you need to merge them together and re-apply the patch. Are those the only errors you get? Strange...

Have you down;oaded just the patch, or the full mod as well? Because you need the full mod before you patch.

There is no "Star Trek" folder in that folder; these are all the errors I get before Civ IV crashes (there may be others)
I did download and insert the full mod before I applied the patch

OK, so I now try running the mod from the shortcut in the "Star Trek" folder. I get the following errors before it crashes:
All Missionary units suffer the same error as displayed above
Then Settler and Warrior units suffer the same error
And finally the four errors shown above occur
*crash*

It looks like something went very wrong in your installation. Could you post screenshots of your Mods folder and the Star Trek folder?

Done; hope this could be something simple like a bad download (though it would be a pain to have to do that again)

It looks like you only have the patch. The patch is just that; a patch. I know some mods do use "patch" when they mean a new version of the full install but in this case the patch is just a patch. You need the full version (the one that says 1.0) and then install the patch on top of that.

OK, I re-copy-and-paste all files into the folders named in the relevant Readme's
I get the exact same 4 errors; the folders look exactly the same (do all folders beginning "ST" belong in the "Star Trek" folder? Doesn't make any difference if I try that, but thought I'd ask)

Well, the lack of "Star Trek Mod" shortcut and ini file in the screenshot means that the full install isn't there. It looks like you have just the patch. Other than that everything is fine.

Re-extracted the original mod; everything works fine now
OK maybe I did fail to do something right (like miss out two essential files. Funny what a difference 8KB can make...)
Thank you people

Those two files I mentioned aren't actually essential, but they aren't included in the patch since they haven't changed since 1.0 I was able to tell that you only had the patch (which is only an update to the full install).