Hi James, i have only played with a few panoramas but i can tell you that you need to do the editing after stitching them together, i suppose it will depend on how much of each image is overlapping but i have seen something similar to a hdr effect when stitching files with a large overlap and this could effect the look that you was happy with before stitching.
The only exclusion to this is to get rid of any vignette that you may have in your individual shots.
My very simple method was to export photos from lightroom as jpg's, open photoshop and bridge, highlight my selected photos in bridge, click on the tools heading, photoshop, photomerge, then select the appropriate photomerge settings in the pop up box, doing it this way you end up with a PSD file in photoshop so its up to you how you export the file from there.
As i said i have only "played" with panorama's, as in a few grab shots or shots taken for another purpose so other peoples experiences with panoramas may be very different to mine.
