What speed do you/should I use for optimal egg and buddy points gain? jogging or relaxed biking? More than 10,5 km/h gives a penalty I think, but earlier I've gained eggs etc quite fast when using 21 km/h too...just don't know which is most effective.
Unless you want to increase your chances of a ban, you should stick to walking speed. Slow and steady for 2-4 hours a day.