How to allow experimentation without losing internet connection?

    "Safe-mode" boot, internal factory backup restore

How to do HTTPS to the local rooter?

    Generated SSL certs, with HTTP connection to add certificate? Verify with
    sticker/paper/screen?

Is 802.11n worth the hassle?

Can an ARM SoC do full bandwidth GigE routing/filtering? Packet/connection
introspection?

Is there existing high-quality software/firmware to act as a wireless access
point (how many nodes?), IPv6 router (cross-platform devices? best practices?),
etc?