What events do the GetEventSummaries and GetEventSummariesByExchange endpoints include in the Corporate Actions API?

Does Xignite have a corporate actions data API? Does Xignite provide private company corporate actions data? Does Xignite offer company distributions data? Does Xignite provide data on company mergers? How do I find a merger event in GetMergers in the Corporate Actions API? Why do some events not have an endpoint in the corporate actions API? Does Xignite provide forward-looking event data? Why are there multiple Takeover, Spinoff, and Merger events in the Xignite corporate actions API? What Is Event Identifier in the corporate actions API? Why are the CUSIP and ISIN fields blank in the Corporate Actions API? What is CompositeIdentifier in the corporate actions API? Why are there missing data points in the Corporate Actions API? What are Optional Payments in the Corporate Actions API? What are Dissenters' Rights in the Corporate Actions API? Why would an event not have Event Notes in the Corporate Actions API? Why does the paid security object in the Corporate Actions API only contains an ISIN? What events do the GetEventSummaries and GetEventSummariesByExchange endpoints include in the Corporate Actions API? Why is there data when searching for Pending IPO in ListListingChanges in the Corporate Actions API? Why are some dividend amounts in the XigniteGlobalHistorical API different from those in the XigniteGlobalCorporateActions API?