This doesn't qualify as a missile system because the init trigger defines some core values, and those values are then used for every single usage of the "system".
The proper usage would be if those values were in the trigger when the unit starts the effect of an ability
This system offers nothing more than a zip-zap movement of a missile which is rarely used anyway.
Basic things THIS "system" lacks:
-A good implementation
-I can't see if this system uses index recycling, if it doesn't then it really isn't efficent as it could in theory get over the maximum array value
-The model of the projectile isn't adjustable, it is HIGHLY object editor dependant instead of being string dependant only
On the end this deserves a 2/5 at the most.