So an article popped up in my news feed that supposedly answered this question but the article is behind a paywall. I don't know a lot about the issue so you can school me if you want.
1. Read somewhere that 73% of England is owned by people of Norman ancestry.
2. England might've stayed out of the 100 years war cause French ties to France likely started that war. I think some of the Normans had large land holdings in France, at least by marriage.
3. The 100 years war helped out the lower classes in England since they participated in the war, some of them were elevated to royalty.
4. I don't know if the Norman brought anything cultural to England, except for fortresses.