See the comments of #3

Here's what I'm thinking:

• Add a IFluidHandler block that holds 1 bucket of fluid ('Basin')
• By default, it will have a lid, and fluids will only be able to put in manually or by some other machine/tank/pipe/etc
• When a redstone signal is applied to the basin, the lid will go away and it will act as a fluid hopper; any fluids that flow into it will automatically be put into the basin
• Dropping an empty container (bottle, bucket, frozen bubble) into an open basin will fill the container with the basin's fluid if its possible

This would both provide a self-contained way to catch fluid outputs of piston crafting and open up some possibilities for self-contained automation of filling bottles/buckets/etc.