Katherine has given you some great suggestions, you will do well in following them. You're getting really close, just two notes:
1. The Robe is a "jedi" styled robe as opposed to the cape the other AV versions tend to use so it needs to have sleeves.
2. I think the belt may be passable for the Armoured Ventress, will need to double check on the references to see if it ever had one like this. Please provide the reference if you have some to consider. Focus your efforts on the other points Katherine notes.
Some informal troops might work OK (so long as you clear it with the event coordinator) to not necessarily have the bald cap so long as the hood is secure, but you'd still need the tattoos on the checks at very least. For you submission photos you will want to have the hood down like in the artwork, showing the complete makeup and bald cap (or shaved head etc). If you need a template for the tattoos you are welcome to print and use ours, available here