It is a electrical code requiring pipe for your circuits in your house!!!
I've been a Master Electrician for 20 years in the Commonwealth of Massachusetts. Running #10 wire is good if you have a long distance to run the wire for voltage drop. For a 20 amp circuit you only need #12 wire. According to the National Electrical code you can put 26 #12 or 16 #10 wires with THHN, (Thermoplastic High Heat Nylon), in a piece of 1" pipe. The THHN insulation is common and has a temperature rating of 90 degrees centigrade. I would use 3/4" EMT, (electrical metallic tubing) as my pipe for this job. You can install 16 #12 or 10 #10 wires in this size pipe. using 2 wires a circuit gives you a maximum of 8 circuits with #12 or 5 circuits with #10 wire. I highly recommend you pull a ground wire, sized the same as the wire you decide to use, in with the circuits. It's not required but it is a better job.

As far as induced noise is concerned, a properly installed piece of pipe will drain any voltages from out side the pipe.. It will not "clean" any noise already on the circuits supplied from the power company.

I also recommend a electrical panel mounted surge protector. This protects the whole hose from any surges on your elctrical power wires.

Hope this information helps you out. Good luck and feel free to ask any questions. Jim