Guard items and Crafting

[archest]

I picked this item up somewhere, dont recall were.
AIRGUARD
It appears to be craftable with airguard intact.

if I were to set this with a item level shard.
Is that all that can be done with this item?

If I were to clean it and ready it for crafting would the air guard remain?

can we get guard item shards back in Cannith crafting?
earth grab , air guard , magma surge.....


or can the existing guard enhancement remain in the item like augment slots, silver , adminine....