Shielding for ICEpower modules necessary? Differences between ASP/ASC/ASX2?

Just wondering if the SMPS in the ICEpower modules require any shielding from other boards (stages) when placed inside the same enclosure. I'm planning a modest integrated amp powered by a couple ICEpower modules coupled with an Arduino relay based stepped attenuator (for IR-based wireless volume control) and a headphone amp stage (which has it's own encapsulated toroidal).

I will be sharing the attenuator between the two stages of the amp, as well as the AC input (will just have a single IEC jack). Will I have to install anything as a barrier between the two? As I understand, any sort of cabling running through the shiled renders it pointless, and as per my plans due to the sharing of the inputs and pot, it seems like a moot solution.

Last question, although not a biggie: Is the regulated 5VDC AUX output constantly on in the ASC series? That way I can power the Arduino setup without cannibalizing a 5V cell phone micro-usd wall-wart?