[Porsche-O-Phile]

They're called pile caps, not footers. The use of a pile foundation system precludes the use of footings (commonly known as "spread footings" which transfer loads to the underlying soil directly).

They can be friction bearing or end bearing. Totally depends on loads and soil characteristics which foundation system is most appropriate.

The connection detail between the pile/cap and the structure above depends on gravity + lateral load characteristics, this is what will determine the rebar configuration, spacing, sizing and layout.

There is no "one-size-fits-all" foundation system. There's not even a "one-size-fits-all" configuration for a given foundation system type. It's all very situational dependent.