Fertilizing trees already under stress will likely only increase the stresses. I never recommend fertilizing until trees are well established, which it sounds like your trees are not. Even when I do recommend fertilizing it is to address a specific nutrient concern and not "just because".
The...
This is inaccurate, black cherry and other cherries (Prunus spp.) are notoriously poor at compartmentalizing (isolating/sealing) decay.
http://www2.ca.uky.edu/agcomm/pubs/ID/ID253/ID253.pdf
https://hort.ifas.ufl.edu/woody/compartmentalization.shtml
What's the loan for?
Sorry, but you don't own the land yet so it's not really yours to do anything with. If your family wants to do something now, then follow the above advice about getting a state/county service forester out to assess and make recommendations as a first step.
Looks pretty old which may explain some dieback. The "growth" is the graft site from where the weeping form was attached to the rootstock. Did CT have any late frosts this year? Many trees around me suffered from a late frost that killed newly emerging leaves. Mostly they are pushing out new...
Could be turkey tail fungus. If so, it colonizes mostly deadwood and serves to decompose the lignin in the wood. No treatment, other than pruning, is necessary.
White spruce should be pre-chilled or stratified to help with germination. After soaking in water and blotted dry the seeds should be stored at 2-4 degrees C for about 3 weeks. Then they can be placed in your growing medium - sphagnum peat moss & vermiculite.
Did you collect the seed yourself...
I'll take a shot...
#1 Spicebush - to confirm, scratch the bark and smell (native)
#2 Honeysuckle (invasive)
#3 Winged euonymus (invasive in most places)
#4 Honeysuckle (invasive)
#5 Mulberrry (see https://www.extension.purdue.edu/extmedia/fnr/fnr_237.pdf for help distinguishing between white...
Looks like a fungal leaf spot disease. Not sure about treatment. Does the tree have a warranty still? Might want to check about replacing with a disease resistant variety.
What you are seeing is a stress response to the defoliation caused by the hurricane. It is typical for trees to try to grow another set of leaves following such stress. Less typical is a second flowering event. It does happen though, particularly for fruit trees such as pears and apples. Those...
Anthracnose is definitely more common in spring and early summer, maybe even into mid-summer depending on weather. Your state extension office may have a diagnostic clinic to test for the presence of the anthracnose fungi.
Sawtooth oak is native to parts of Asia. In North America it is mostly planted for wildlife, especially turkey and waterfowl which like the small acorns that it produces. I've heard the wood is weak and prone to cracking.