The point of shingling is to hit the nail not your fingers! LOL Man I'd like to try some of your pot. It has to be GREAT! Ow, ow ow and yeah I know you know. In your case I'd use Neosporin on the small gashes on your index and middle.i probably shoulda worn gloves when i shingled the roof the other day.
Hub is an A&P, he used to gripe about someone he referred to as Freddie and his 30 feet or 30 sec guarantee. I miss his aircraft hands ;/No, but I know who they are and I know some asshole that worked for them. Do you know a guy named Fred that wears glasses and everyone hates? He worked for us for a little while. He came from dyna-corp and worked at ft Campbell.
Btw, I'm also a airframer
As for persistent cracking hands try Neosporin see if that helps.