Agree about guest pages, (as long they don't require installing self signed certificates that are later used for https inspection) - happened to me once in a nice hotel doing not so nice things. But as you said, this will be a simple disclaimer and an opportunity for user to known more about "City & GridCoin Sponsored Wifi", which could be a good read while waiting for a buss.

As for the cooling, I was unsure at the moment of order. But since the LAN chip is going to be active all the time - connected to Raven Airlink Device via ethernet, i was thinking it's a good idea. Anyhow, it should not hurt.

SD-Card issue, good point, I did not think about that. Will test it under heavy load and try to calculate how much it could be expected in terms of durability.