Answers:
1. no
2. no
3. maybe?
The Solix/Onix platforms will share waypoints only when networked with your 999/Helix platforms. So to my understanding, if you're using the GPS puck on the 999 to mark waypoint and you're sharing those waypoints with the Solix via the network, that should work, but I don't believe you will be able to locate the 999's GPS puck on the Solix via the network.