Can you retrieve an enemy's attack IDs with plotscripting?
Yes, you can.
All enemy data that you enter in the Edit Enemy Stats menu can be accessed with commands plot:read enemy data and plot:write enemy data. get/set enemy name/stat/appearence are wrappers around these commands.
For example, to read the first normal attack from the enemy with ID enemy, you would use
normal attack 1 := read enemy data (enemy, 92) -- 1