Query #1: It is possible to change the background color of single date (or a set of dates) in sfCalendar
We have prepared a sample which tries to meet your requirement. In this sample we have used Cell Template Selector to change the Background color of the cell with three cases Friday, Today and Default .Similarly, you can change the background color with the set of Dates based on your need.
Kindly download the sample from the below link:
Please let us know if you need any other assistance