Task fields are not visible for a page layout, e.g. anything related to recurrence, reminder date time and similar.
Why? Can they be made visible?
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The fields you've listed are special. End user doesn't have direct access to them, instead he can work with more user-friendly interface.
Also some of them are deeply technical (user's don't need to know that child Events are how the system stores info about recurring Events as long as they're displayed nicely in the calendar).
Why do you need them? You might try to build a formula to display them or maybe a VF page... I wouldn't be surprised if they'd refuse to work with
<apex:outputField> and require outputText etc instead...