You can also experiment with minimum mapping units (lengths), placing the labels at different offsets
from the beginning of the line to keep short segments from being labeled (also looks a bit better than labeling anywhere that fits). Offsetting the label from the road a bit may keep crooked streets from labeling "crookedly" or at all. I would also exclude ramps and unnamed streets and such from labeling, if you have fields that could help you do that.
In general, it is a lot easier to spend the time getting 90% of the labels you want by tweaking Maplex once, then adding the few most important ones than it is to get into adding, deleting, and moving annotation. You can always force the most important segments to label by putting them in their own labeling class with a high priority and buffer.