BH,

You are correct - wherever you place the first note of the minor pentatonic scale is the minor key you will be playing in. That's why it's important to learn the notes on the two lowest strings.

As far as getting more variety out of the scale, try mixing up the order of the notes as you solo, by skipping notes and playing different sequences. for example, start at the first note of the scale, and play three notes up the scale; then start at the second note of the scale and play three notes up from there. There really are endless possibilities for the pentatonic scale. Be sure to learn all five patterns of the scale so you can play all over the neck in whichever key you are in. I have a free pdf file with the diagrams for all five pentatonic shapes with some explanations on the articles page on my site if you would like to grab it.