I didn't realize that hosting the css externally could have that much of an impact. Hmm... I've always hosted internally but then again I'm no expert on this.
Just FYI I removed your link. When you have enough posts to have a sig you will see the Edit Signature option in the Settings. Spam is a big problem here and we often have new members post a bunch of posts just to get their link out. So that's why links are only allowed in sig and there is a minimum requirement. Thanks for understanding. Welcome aboard!