Excellent point ArKay, jpg should be the last step in completing an e-comic file. I favor scanning to PSD files for editing and storage, which was difficult until larger and cheaper external storage drives became available. PNG has become popular and is another good alternate to jpg, although I've used the older TIFF format with a great deal of success. The resolution is much better with these formats and allows serious editing, down to the pixel level.
Another reason to use PSD file format in editing.... page alignment. Sometimes a scan will not be square due to the staple alignment, damaged page etc and you need to rotate to square a page. I favor PSD for this operation and you're right tilliban, “ you are entering a world of pain”
but that's the challenge and fun of using a program like PhotoShop. Using the PS Free Transform tool under File will rotate a page nicely.
There is also something I call “scanner distoration” where the bottom of a page is smaller than the top due to problems with trying to flatten a page for scanning. The PS cropping tool has a setting that allows you to square up the art, a little tricky but worth the effort.
Just some of the fun in bringing the old comics back to life