David,
Sorry about the delay. For some reason, the notification function that tells me when someone posts a question was turned off for a long time. I realized that a while back and got it fixed, but missed your post. When Ryan posted, it did send me a notice.
Ryan has posted a clear answer to your question and I agree with him completely.
The 1 finger for walking is the standard set by many masters. Some great players do move the wrist like pumping the gas on a motorcycle. The fact that the energy does not go into the production of sound on the bass when you pump the wrist makes sense to me. That is why I don't play that way.
Rufus Reid is a master and gets one of the greatest sounds ever. Here is a recent video that shows his right hand extremely well:
http://www.youtube.com/watch?v=pPzrUfvVstc He does pluck off of the board when he plays really high, but usually it is at the end of the board.
Here is Ray Brown with the 1 finger (and notice for a moment his 2nd finger!) :
http://www.youtube.com/watch?v=2l5CHNypezY
Mingus when he is walking (and with a great close-up at the end when he is soloing fast with the 1 finger wave)
For soloing, I agree with the two finger perpendicular technique you mentioned.
Here is John Patitucci using it well:
http://www.youtube.com/watch?v=wKg_2GIPNuY
I hope this helps too!