I don't think its bacterial canker.The yellowing of the leaves with the dark spots is most likely fungal.Bottom leaves just yellow and falling off could be excessive watering. The bumps on the stems are normal. Roots would form the "bumps" if the stem were covered with dirt or water.The bud drop could be enviromental.

Check the problem sover 2 thread and go to the 2nd post. Open the link up and check out pox and flecks. I have attached a picture.

Good luck

Here is a link that might be useful: pox and flecks

Tom, thanks so much for your help. You are good at this! :) Yes, that's it, so they have fruit pox. I guess I wasn't too far off saying it looked like they had chicken pox. lol While I was looking at so many pics of spots, I got it confused with bacterial canker because they both had indents in the center of their spots. I realize now that they are pox.

According to another site (link below), it's not fungal, bacterial, or viral (whew, what a relief!), it's genetic. Does that mean the fruit is edible? No one seems to mention whether it is or not, they just say it's unsaleable. I do have some fruit on the other plant that doesn't seem to have spots yet. Some may have a few spots, while others next to them have none that I can see. I have to admit, I don't find weird "pox" all over my tomatoes to be too appetizing, but I'm just curious whether they can be safely eaten or not.

How common or rare is this disorder? What if I grow this same tomato again, but start over with fresh seed? Is the same thing likely to happen again? Temps should start getting cooler soon at least, which might change the growing conditions somewhat.

Here is a link that might be useful: More on pox and flecks