1. The task of selecting guide hairs seems completely impossible. When I try to select the guide hairs on the front of the head, it's as if the head object is not there to block the hairs at the back of the head from being selected as well.

It's a bit tedious, but not impossible. Use those preview settings balls. Wireframe, hidden line, etc. One will let you select the opposite polygons (convenient for symmetry), while another will only let you select polys on the side facing you.

I also recommend Softriver's tutorial. It's the best I've seen for detailed styling.

2. Calculating dynamics seems to undo any of the so-called "styling" you succeed at creating with individual guide hairs.

You don't have to use dynamics, and you can adjust how much the hair is affected by dynamics.

For dynamics, consider buying Kirwyn's "Genesis Hair" in the Marketplace. It's well worth the $8. In addition to a great tutorial, you get hair and low-res "proxy figures" for most of the major female characters. This lets you calculate the dynamics very quickly. Then you can substitute the higher-res actual figure, and if necessary make the hair higher-res for the final render.