I have a few questions.
Are long shuttle coasters allowed?
does it minds if arms might hit the border of the area where the track must stay in?
1. Any type of coaster is allowed, which includes shuttle coasters.
2. If there is any type of support that would endanger the guest, it is considered a collision. However, if the border is in the way, you can adjust the height. You cannot adjust the horizontal position of the template, because it would change the interactions with the rings, but you can raise and lower the height of the template itself all that you want. (the enclosed area does not change at all, so it doesn't matter.)