I agree with both. And it depends on how the grips are treated too. Grips are all slightly beveled or rounded at the top, but I've seen some shops put them in so far and then take a razor to cut them off flush with the ball, that creates a REALLY sharp edge, and not the way to go. Changing grips would be the cheapest, easiest first stop. However, the lack of reverse pitch in the fingers is staring at me, grips won't fix that, especially with 0 pitch in your thumb. Without seeing your hand on the ball, I can't know for certain, but your specs look reasonable with the exception of the lack of reverse in the fingers, I would echo Brian saying that 1/4 would be a good place to start. You do say though that your middle finger gives you the majority of the problems, and that may be because the span is longer to your middle finger, so you're going to be middle finger dominant. Instead of using both fingers equally, you're most likely really relying on your middle finger to get the majority of the work done. In what you said, you've got the right ideas and the right concept, it's just locking down what works for your hand. Here are links to my videos on fit, this might help you out as well, particularly the story I've got in the second video, one of my buddies had a really similar problem with his fingers.
Part 1 -
https://www.youtube.com/watch?v=WLlLKku5l2UPart 2 -
https://www.youtube.com/watch?v=G-KGGPLcU80Part 3 -
https://www.youtube.com/watch?v=XV634xL1iBgI'll also second itsallaboutme on the going to no grips thing, you'll feel like you're losing it initially if you aren't used to it. And once you get used to grips, going backwards might be rougher on your fingers. The less bevel the better. If you're cutting yourself, it's because you're using the creases of your fingers to get the leverage instead of the pads like it should be. Adding reverse will bring the fingerholes back to contact with your finger pads. It sounds like you're pretty versatile, and it sounds like the top end of your rev rate when you need to crank it is pretty high. Reverse in the fingers sounds exactly like what you need. HOWEVER, you will have to make small adjustments, most likely to the span, to keep your fit balanced. If you go reverse in the fingers, it's going to make the span feel shorter, so be aware of that. I don't like making several adjustments to fit all at the same time, because if you go step by step you can put a fit together better, but I also realize that plugging a ball a million times is time consuming and expensive. Spend some time with your pro shop guy on a fitting ball, I know it's hard to get a feel with a fitting ball, but you might be able to identify some things. With 1/4 reverse in the fingers, I'm betting that an increase of 1/16 in each side of your span will be needed.