Ah! Nero *has what I need* in the Properties section

I was mistaken: it IS possible to adjust track separation times, it's in the "Properties" menu for the tracks on the next to last step before burning. Also, there are some effects as well, including a graphic EQ, and two methods of normalizing the track volumes. I am optimistic. I have created a disc with 12 tracks that comprises what should hopefully be the final track listing and ordering.