1. You would never say "Our English teacher often creates an occasion in class for us to communicate like native speakers", it sounds unnatural. You would say "Our English teacher often creates a situation in class for us to communicate like native speakers"
Although situation and occasion are technically the same thing, an occasion is used more for a special event like a wedding, a date night, a holiday, a birthday, etc. A situation is a combination of things occurring at a particular time that are connected to each other.
2. Both are fine to use, but in this case, value sounds more natural.