B: Late Input Events: events that arrived later than the configured late arrival tolerance window.
Note: While comparing utilization over a period of time, use event rate metrics. InputEvents and OutputEvents metrics show how many events were read and processed.
D: In job diagram, there is a per partition backlog event metric for each input. If the backlog event metric keeps increasing, it's also an indicator that the system resource is constrained (either because of output sink throttling, or high CPU).
Reference:
https://docs.microsoft.com/en-us/azure/stream-analytics/stream-analytics-scale-jobs