The first is sassafras. The star shaped leaf is Sweetgum, Liquidambar styraciflua.

You have a Tamarisk. My advice would be to kill it. Out here, Utah and most of the west, they are invasive weeds. They have taken over much of the riparian lands here and have choked out much of the native vegetation and animals. Aside from producing literally thousands of seeds a year, they have very deep tap roots, often going down over 20 feet. They will lower the ground water below where other plants cannot reach it. This reduces competition. Another way they reduce competition is by taking salts from the ground and water and secreting them from their leaves onto the ground. Over time this raises the top soil salinity and, again, reduces competition. These are very tough plants. We have had summer with no rain for three or four months, and they do not seem to have been bothered at all. Even fire will not kill them, they just grow back from the roots. They also associate will a bad crowd. Siberian Elms, Tree of Heaven, Russian Olive, you know the disreputable type. Recently, a beetle has been imported from the Mediterranian area where these things come from. It eats only tamarisks and seems promising in at least thinning them to allow the natives to come back.

The insects in pics 2&3 look like giant bark aphids, Longistigma caryae. They don't normally infest cherries but perhaps the tree is stressed for another reason and is just vulnerable to insect predation. Typically any sort of garden treatment for aphids will control these pests - a strong steam of water, hort oil, neem oil, insecticidal soap, etc. I can't see the raised brown lesions well enough to determine if they are more than just normal cherry bark lenticels, although they look a bit too regularly spaced for lenticels. Is there any sign of a sawdust-looking substance at the base of the tree or hanging from any of these lesions? That could indicate borers, a common cherry issue. Is the tree otherwise healthy? Good foliage development, proper flowering, no stem or tip dieback? Black knot usually presents in the branches first and moves down into the trunk when the disease is well established. Any swollen, blackened nodes in visible in the branches?

Viburnum lentago.