I know how scared and concerned you are.
. You have done a great job giving them the very best opportunity for success.
To answer some questions: I don't think it's possible for you to keep them out of the pine tree by the RC. Once they get out they will want to explore everything. They may stick together, but they may not. Sometimes it takes awhile for them to have the courage to venture out, which is why you leave the cage open till dark, just in case they want to come back inside. Many will continue to sleep in the RC for several nights.
I only had two boys to release, and keep track of, but when the day came I released around 9:00 in the morning and literally sat in my backyard the entire day keeping track of where they went and playing with them. As I've said before, I didn't follow protocol and stop all interaction with them.
I also don't have a major hawk problem here. My guys became much more savvy as time went on and seemed to learn even more from the wilds after released. They were in the RC for 2 mths and were probably 6 or 7 mths old when I released them. They did return to the RC to sleep for a few nights, though. They are still living in the oak tree that the RC sits under so they can get the breakfast buffet every morning.
I wish you the best of luck. As long as your guys are old enough and spent enough time in the RC then there isn't much else you can do, but hope and pray and be visible for a few days to try and thwart any predators.
Keep us updated, please.