DayZ Standalone IS NOT ArmA III - DayZ Standalone is not a Modification, its an alone standing Game.
1) You dont need any further Programs for Scripting, PBO-Manager is a good help to look into Scripts used by Bohemia.
- Notepad++ will be the Thing you use the most.
2) ArmA 2 Scripts are mostly the Same as the ArmA 3 once, so what means this? Tutorials will work mostly the same.