AppleScript for iCal events from Address Book entries
To set single alerts on all birthdays, you can avoid a script altogether:


Open Calendar Preferences in Calendar.
Under General, tick "Show Birthdays calendar".
Under Alerts, set an alert for "Birthdays".


I haven't taken the time to actually write up an AppleScript for the double alarm parts, but this article seems to cover scripting calendar alarms quite nicely. I would imagine you would just need to create a file or list in the script that contains the names of the events (which you can deduce from the standard naming convention Calendar app uses).

Also I am using Mountain Lion with Calendar app. I can't recall if the steps above work on older versions of iCal.