Doesn't matter. We have stack of storage space on the server anyway. Who cares about 70kb when just one of the Sources files for the forum software is 150kb?
I have thought about loading either jQuery or MooTools. If you want to try it that's fine with me.
I'm not familiar with MooTools. JQuery is more advanced I believe, it certainly receives a lot of attention from developers all over the world. If we decided to use jQuery, we should definitely let Google host the file for us.

Anyway I did think of one thing with this quote splitting. At the moment you have to use keyboard and mouse to split quotes (given that most people will position the cursor by using the mouse). It would be cool if the whole process was mousable.
Yeah, maybe that's possible. Perhaps assign the function to Ctrl + Left Mouse Button?
I will enable the checkbox for the quote splitting feature by default. Tell me if you think that's a bad idea. I think it shouldn't affect anybody negatively.