Multiple Arduinos (arduini?) into Pure Data w/Firmata

Currently in the planning stages of a larger-scale installation that will use many arduinos with a large amount of sensors (though, obviously there will be more than one computer). I am very comfortable in Pure Data, so I know the limits there, but I am only starting to get familiar with Arduino. Since I currently only own one arduino unit (an UNO), I haven't been able to test out how Firmata (w/ Pduino) would work with multiple arduinos. I have two major questions:

  1. Is it going to be possible to run multiple arduino's through the same pduino patch? If so, how many can safely/reliably run?

  2. My experiences with Firmata into Pduino have been only slightly successful at best... when using more than one sensor, what is the best way to reduce 'noise' for all of the analog inputs? I've been scaling data in PD, but that only works to a certain extent... is it a hardware problem (i.e. my probable lack of circuitry know-how)?