Do I have to use my last alignment star for the All-Star polar alignment? What are some other tips for convenient All-Star polar alignment?

No. Nor do you have to know its name.

Find a bright star close to the meridian. Choose one at or below the celestial equator in the south (for mid-northern latitude observers). This makes it easy to work at the eyepiece and also reach the fine adjustment knobs in altitude and azimuth. Slew close to such a star. Then use Identify. The star should be the top one on the list. Press Enter and your scope will start to slew to it. Press Undo immediately to get to the top of the menu and then press Align. Choose Polar Align > Align Mount. Your scope then completes (re-slews) to the star that you just identified and goes through the All-Star polar alignment.

To update the alignment: the simplest way is to cycle the mount's power and do another two-star alignment with calibration stars.

Updated 12/15/13