Internally, ExclusiveWaiters is a pointer to KEVENT and SharedWaiters is a pointer to KSEMAPHORE.
NumberOfSharedWaiters/NumberOfExclusiveWaiters are essentially what they are named and are used to check the waiting state of a resource (either shared or exclusive).
The so called "fast" executive resources are used internally by the file system stack and provide somewhat more optimized performance in some scenarios.