At 10.0 Image Service supports Identify. Can this data be published as an image service?
1) Colormap doesn't support mapping a range of values. The workaround is to apply stretch function or arithmetic function (to stretch/squeeze to unsigned 8 bit) and then apply colormap function. This is what's applied to this temperature service:
2) "Time Value Format" is applied when you use a string/number to represent date. You don't need to specify "Time Value Format" when it's a date field.