The webbing ontop of Jackie is cut and replaced frequently. I beleive the reason is that it is close to the walkoff, and when people rap from the top of P2, it further crowds the already crowded Jackie/Classic/Pink Laurel Ledge.
I am certainly not the source on if it is ok to add new rap stations or not, but I would think it would be ok to replace existing slings at anchors and trees, but I would say it is probably not a good idea to add new rap stations. One reason is, as you said, it could be seen as littering and a bit of an eye soar. The other reason is that someone will most certainly cut your new slings if you try to build some sort of a new rap anchor. There is an easy decent option from just about anywhere in the Trapps already. Whether that would be a rap from that particular climb, rap from a neighboring route, or a walk off.