A little confused about VX Ace's RTP

The help file states that the RTP contains "standard graphics and audio resources." I am using a combination of original graphics, original sounds, and existing sounds from a vanilla project. Do I need to add the RTP when I create an archive?
 I assumed it would add any resources I had in-project, or are the vanilla resources not added to the archive unless I manually import them/add the RTP?

It doesn't matter if you choose whether or not to include the RTP, your own custom graphics will be included with your project. The only reason to include the RTP is if the person(s) you're giving it to don't have RPG maker installed. If they don't have RPG maker then they won't have the RTP.
Most people who play RPG maker games will have the RTP anyway, because they usually also use RPG maker. So most times you don't have to bother including it.

Thanks!
Let's say they don't have the RTP though, and I'm using some of the sound effects that come with VX ACE. Would I need the RTP then?

Yes.

Thanks, I really appreciate the help with this, and the cat butt issue the other day.