Multiple Categories in Restrictions
Copy the way the 'Days' criteria works in restrictions, where you are able to select/deselect days in restrictions to other criteria such as Rate Group and Space Category etc. this will save time so you don't have to create a new restriction for each rate Group and space Category etc.
Wolfgang Schlicht commented
A select box for Rates, Rate Groups etc. where you can tick the rates etc. this restriction should apply to would be great, since it minimises mistakes and saves a lot of time, especially when you have multiple rate groups that do the same for each channel like booking, expedia, homepage etc.