This doesn't seem to be Debian-specific. I tried a number of other distro's live installers on USB -- current versions of Ubuntu, Arch, CoreOS, Fedora, Puppy, System Rescue -- and experienced boot hangs at various points with each.
After much fiddling with ACPI kernel boot parameters, I was able to get reliable boots using 'nolapic' -- which effectively reduced the system to one core. I subsequently narrowed it down to working with 'nolapic_timer', and after comparing the dmesg output of 3.2.x to 3.16.x, began to suspect the underlying problem was related to intel_idle -- which was disabled for the Atom N2000 family under 3.2.x, but enabled in 3.16.x ... I think this is the commit: http://marc.info/?l=linux-pm&m=139068510624936&w=2 In the end, I found that I could boot the 3.16 kernel with: intel_idle.max_cstate=0 which seems to effectively disable intel_idle and fall back the ACPI idle driver. Cheers, Chad