Vatican II, approaches to liturgical change, and the importance of culture

The Second Vatican Council suggested changes in policy and regulations; it didn't define any doctrine.

I regret to inform you that it did. Given that it was billed as the succeeding Council to the First Vatican Council, it (V2) was granted the same infallible status as V1. (Not to mention the heteropraxis of V2, but there is more than enough material on that from both Catholic and non-Catholic