The old files area at planetvampire.com is no more and we won't be fixing it. Basically, we are leaving IGN/Gamespy entirely and have started a new site "planet-vampire.com". The new site has much more flexibility and with a new files area that also has the ability for you to upload content. Before, I had to do things manually and each mod I added took about 20 minutes, which was insane. anyway, you can find all the new files here:
http://planet-vampire.com/modules/files/
The Redemption area of the site is just getting started. Basically I started working on it and thought (along with Javokis) that we needed someone else to completely redesign how the content is displayed ect to make it look newer, vs the screenshots taken when people were playing Redemption on a 486 ect. Someone is working on it right now, it's going to look pretty cool.

Hmmm. Are there any stand-alone mods that allow you to play new and different single-player stories? Or do all of these mods merely change rules and add objects to the base game?

It is possible to create new chronicles but sadly I don't know of any. Javokis made video tutorials on how to make them however.
http://www.youtube.com/profile?user=javokis#g/c/4ED1E193E87CD31E

I've just been wondering this as well, surely there must be some chronicles around?
Is it possible to make enemies spawn automatically and are any good mods that improve multiplayer?

If you mean to create a scenario where the game kinda reacts to your premeditated story by scripting them to spawn then no, not to my knowledge anyway.
E-mod can improve MP by allowing character animations, flight, jumping and other things. Scripting items to move, such as cars on a map can be done using the Particle Mover. However, the PM cannot run at the same time as E-mod. I've been told it would be possible to combine both mods but it will not likely happen.
Here is an example of what you can do with Emod and the Particle Mover. I shot them separately and edited them together:
http://www.youtube.com/watch?v=B_Mq-KmEjN4

Looks good but im just a casual player and was wondering if theres any mods that add new game play, like chronicles and maps?
I don't really have the time to make my own, unless its quickly placing some enemys around a map and fighting them and thats not really very interesting, though it could be more fun if i could get them to keep respawning once i've placed them, thanks though. :)