The Roku actually runs fine without an internet connection. It does requite an IP address (can be local) for development work, and possibly for
initial setup. I've booted my Roku with no network connection and run KidPaint, and I'm fairly certain renojim (and others) have done the same with Video Poker.
You really need something acting as a router. Whether that's your computer or a dedicated device makes no real difference, and whether the router is actually controlling access to the internet makes no difference. What it's really used for is to hand out an IP address using DHCP, so the Roku knows how to access whatever network it's connected to, wireless or ethernet (you probably know all this).
If you are seeing different behavior, possibly you haven't finished initial setup?
Edit:
From the other thread I think I'm seeing your point now. You need it to get an IP for the demo, but there's no internet access and the initial DHCP setup fails. I haven't tested this case so I can't comment on how I've seen it work, but if it indeed will fail getting a DHCP address without internet access, that would be a problem for demo purposes.
-- GandK Labs
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