I am confused too.
I think it would be a good idea if you describe your project in more detail. It is unclear how many and which pins you are expecting to use and for what purpose.
Just to be clear that we are talking about the same:
The Capacitive Sensing Library ned a sense and receive pin
http://playground.arduino.cc//Main/CapacitiveSensor?from=Main.CapSense
If you are using TinyISP and knockbang , the serial output form attiny is pin PB1 (physical pin 6) connected to pin pin 12 on the UNO,
This is also the reason why you should not use this pin as sense pin, as I tryed to explain
That leaves you with 2 pins (three if you use the reset pin)