Is there a way to select only a portion of an edge loop?
You can to a certain extent by selecting two vertices on an edge loop with a gap between them, press W to get the specials menu up , select > select vertex path from the menu,then distance method > topological .
This will selected the vertices inbetween your original vertices going the shortest distance between them on the edgeloop.
Here’s a trick that’s really proven useful. Select the edgeloop (as above or with Alt-click), then boundry select with the circle selector, B key B key, and use the middle mouse button to deselect the unwanted vertices.
Also very useful in tight corners if you select a single vertice and then add all it’s neighbors with the num-pad plus key.