Scanning raw cards

[Jenx34]

I'm struggling to scan large #'s of raw cards to prepare for sale. Can anyone offer any tips on the quickest/best way to do so. Could include fast/good scanners, general methods,etc. Here is what I am doing now.

Using a flat all-in-one printer/scanner. On my Epson I can do 3 cards at one time and then crop into individual files using Photoshop. I switched today to my wife's Canon Pixma MG7520. With slightly more space around me, I can scan 6 cards at once, but on both I still have trouble getting cards lined up straight. About every 3rd scan at least one or two are slightly askew and I have to re-scan. My eyes aren't sure enough so I use a group of top loaders as a spacer between the cards and the edge so I can get a border around all sides. Even then, I can't keep them straight and have had to live with a certain degree of crooked. I don't know photoshop well enough to straighten the pic once I've cropped it. Any help in that regard would be greatly appreciated. But obviously the goal is to do as many as possible as quickly as possible. Yesterday I scanned 130 cards front and back. Took me 8:30 of actual scanning time. The best I could do is 15-16 per hour.

Also, is 300dpi too high for raw cards? I've found sometimes the scan is picking up things I can't see with my eyes holding the card in front of me or even with a basic magnifying glass. Some scans make the cards look worse than they they look in person.

Lastly, I've read a lot of threads about scanning graded cards and the recommendation of CCD technology. Does this matter with raw cards? I'm attaching a scan of two graded cards I just scanned. Can anyone tell me just by the scan if the Canon MG7520 has CCD?