The closest spread to peanut butter I've found in terms of flavor and texture is sunflower seed butter. It's also relatively easy to find; I've seen it in large chain grocery stores right next to the peanut butter.
A curmudgeon with years of practice. The bubbles in boiling water are steam or vaporized water. The bubbles initially do not reach the surface of the billing fluid as the colder water away from the hot bottom cools the steam turning it back to liquid. WHen all the water is at 100oC the bubbles reach the top.
Bubbles can indicate either a physical change (a liquid is boiling and changing from liquid to a gas) or a chemical reaction taking place. This image is of a gun where the serial number has been filed off. By adding hydrochloric acid to the that area, the serial number can often be restored.