The reddish, also the one dark, critter probably aphids. (A little tough to be certain as pretty fuzzy.) If so, direct hits of insecticidal soap work.

Green fellow are aphids. The white things in some of the pictures are cast skins of aphids. Again, insecticidal soap.

The final picture is root initials on the stem. Often indicate the plant is stressed.

They are aphids. Hard spray with the garden hose will ruin most of them. You can go back later and use some Safers Insecticidal Soap which should control the rest.

Those bumps on the stems are called "adventitious roots". Google them for more information. They don't necessarily mean the plant is stressed but they appear when there's moisture, even in the form of humidity, that encourages their growth. Tomatoes are so prone to putting out roots they will root all along the stem if they come in contact with soil.

Thanks everyone!