Hi Jeon Jongin,
For acciaccatura and appoggiatura grace notes right click on the note you want to add a grace note to and go to the "Add Grace Note" menu item. You can also convert a note into a grace note by using the "Grace Note" menu item.
As for arpeggio symbols, we do not have them yet. But they are on our list of symbols to add. They should be available in a coming update soon.
Regards,
Ben