THE TANK:
When right-clicked, opens a GUI that looks like this: https://ibb.co/p3JpQWC (excuse the ms paint)
The items displayed by the gui are meant to be all the registered liquids in the game. The bar at the top is a search bar. There should also be a scroll bar on the right.
Clicking on a liquid will make the liquid be displayed in the top left of the gui. That liquid can then be extracted from the tank with any pipe or conduit.
THE "ITEM GETTER"
When right-clicked, opens a GUI that essentially looks like the creative menu, but with an additional tab containing "hidden" items, i.e. items that have been registered but are not displayed normally/hidden in JEI.
The player can then take items from the GUI in the same fashion as the creative menu.
THE ENERGY SOURCE
Infinite energy, instant transfer from all sides. It powers all tile entities in a 3x3x3 range centered around itself, wirelessly.