For the RAM question, 960 MB is what it says in the system tab but it is a lot slower than when it was new ten+ years ago, though that might not be connected to RAM.
Since I saw your post I have both tried bouncing the master with the group track which has all tracks within bounced and removing the group tracks and bouncing all tracks individually followed by bouncing the master, both have resulted in the same thing, the master cutting out at the 16th bar.