I have a comment regarding Task (2).
In my opinion, you should swap the functions assigned to 1) and 3).
When someone says: 'The dam is going to break', there must be some evidence to such prediction (extraordinarily high water level, even cracks in the dam wall), although it's not quite clear from the context. On the other hand, 'He'll be 18 on Saturday' is a definite future event (if anything about the future can be certain at all. But that's philosophy.)
Apart from the above, I think your classification of the various future activities / events is OK.
All the best,
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