Depending on the issue - response times will vary wildly. I've had between an hour and a day. before getting a response.
As for backup frequency and location.. to be honest, no idea. One would hope though that the data was not stored on the same media as what have been a rutt of failing raid cards and duff drives..
Uptime policy you can find in the terms of service, I believe for each hour since you reported the issue you get a free day worth of hosting up to a certain amount. (I've seen the specifics before but do not recall where unfortunately).
Plans incase of service outage? - You need to have a read of some of the other posts around this forum..
If there are any plans, they aren't very efficient =3