Yeah there will be some bleeding into the natural areas. clean lines cannot be stained, you'd have to fade or burst them in using a sprayer or airbrusher. Painting stripes is another option. Paint after staining.
Regardless of what finish you do, the hardest thing you'll be dealing with is sanding down that red stain and the clear coat above it. You may even have to sand through the first ply in doing so. If you're that adamant about a stained set with effects such as stripes, fades or bursts then maybe you should think about investing in some keller shells and just swap out all the hardware from the PDP set. Keep the red shells just in case you want to go back to the red someday or just ebay them to recoup some of the money spent. It's pricier doing it this way but it's going to be horrible if you ruin a shell and decide to not do the project, and then recover it to match your PDP, because your red set is actually a very nice looking set.
Set 1: Self built custom drum set
Set 2: Ludwig Accent
Cymbals: Meinl Byzance Traditional, Meinl Byzance Jazz