Does anyone know if I would achieve better results from a flatbed scanner of equal or lesser value to my Rebel, when scanning original artworks (mainly drawings)?
There are no digital cameras that I know of that have anywhere near the resolving capability of even a cheap flatbed scanner. If you can find a flatbed large enough for your drawings then using that to copy them would be far prefferable. However, A3 flatbeds tend to be much more expensive than A4s. It's really a matter of how much detail you want to capture. If you are not likely to print greater than A4, then the Rebel will be quite adequate. If you have to stuff around stitching two scans because the drawing is larger than your scanner, then using the Rebel would be prefferable. If you want to make huge enlargements of your drawings, so sharp that the texture of the paper is clearly visible, then a flatbed would be ideal.