I'm going to weigh in with a contrary opinion.
I don't think the guide-rod is OK. If you got a plastic rod, then you need to shoot a plastic rod. I know it's a production part, but not in YOUR gun. Replacing the guide rod was not covered in the list of allowed mods.
"g. Action work to enhance reliability (throating, trigger work, etc.) is allowed." I know there is an unknown amount of room there in the "etc.", but that's what I think.
Also, If the base pads on the magazines are add-on, then those aren't kosher either. There was a BIG discussion about magazine lengh on the IPSC mail list and the opinion of John Amidon, chief RO or something like that is that magazines should be of the same overall specs as factory mags. Therefore, if the rubber pads make it longer, then it is not OK. Now, I will be the first one to admit that the rules do not support that position well. But that was the intent.