Using SMS Scheduler option, you can predefine SMSes which needs to be sent at a particular Time or Date. For Example, you tend to forget birthday of your friend in such scenario you can define the SMS for her/his birthday on her/his birth date & time you want to wish her/ him.
Yes. SMS Charges are applicable (separately for Local and National).
You can check your scheduled SMS list in 'Scheduled List' option.
You can check history of your Scheduled SMS in 'Scheduled History'.
No, it is sent like a normal SMS.