1) To power your Disnortion use Pedal Power 2 Plus output 5 or 6, DIP switch set AWAY from NORMAL and one of the all black (standard polarity) cables supplied. Or, use the voltage doubler cable you describe in outputs 5 and 6, DIP switches set NORMAL.
2) Yes, you can use the output on the tuner as you describe. Or, you might consider using our output splitter adapter.
Our output splitter adapter (part# PPAV $6.00ea.) is a 6 inch Y cable that connects with 1 Pedal Power DC output jack converting it into 2 output jacks. This allows the connection of 2 cables to power 2 effects/pedals from this single DC output.
Note: Pedals powered from the output splitter adapter must be standard polarity (center negative) and their combined current draw cannot exceed the current limit of the output to which the output splitter adapter is connected. Also, one lead of output splitter adapter has its ground lifted to prevent the ground loop hum/buzz typically caused by daisy chaining.
You can order our cables and adapters online.
To do so, please visit our Cable Purchase web page.
Here is the link:
http://www.voodoolab.com/shop/index.php?cPath=22 