Okay. Finally got round to mission 7.
1) Your ships are slighty off of the the X axis. As a result the subspace tunnel looks a little odd in FS2_Open. (I also kept flying to the left trying to adjust for it!

) Just drag everything about a km to the left and you should solve that.
2) The Julius slows to a stop in front of the node because when you give a ship waypoint-once orders it will attempt to stop at the waypoint. You should instead use the distance SEXP to check if the Julius is nearing the waypoint and then simply give it orders to jump out.
3) I never actually saw the Julius jump out as I was too busy trying not to die but you've got the waypoint slap bang in the middle of the jump node. FS2 ships open the jumpnode a fair distance in front of themselves so that they can build up some speed. As a result I'd be willing to bet that the Julius' jump point is actually outside of the jump node. Move the node back a few hundred metres (you'll need to experiment as I can't remember the exact jump out distance for the Deimos) so that the jump point from close to the centre of the jump node.
4) The Jump out message from the Julius is actually sent from command because you've timed it to appear after the Julius has departed.
You can get a message to appear from a ship not present in a mission by changing the first argument of the Send-Message SEXP so that the ship name has a # symbol in front of it (Like the way messages always come from #command not simply command).
In this case however I feel it would be better if the orders come from the Julius as it prepares to jump out not after it's gone.
5) The Julius tells Alpha to get to the jump node and jump out if the engines fail but there is no way to jump out. A fix-warp and a failure debriefing is one way to solve that.
6) Some more messages from the Julius might be nice
Apart from that it was a pretty enjoyable mission.