It was said "Stop pruning it. ... they bloom on old wood" Well, sort of "old" wood. They bloom on last year's wood. So, the key to a full crown of bloom each year -- ignoring possible nasty weather events -- is to prune every year right after the bloom is gone. If you wait until later in the year, you will remove the buds that set beginnng in July/August. The new wood that grows this year will support next year's flowers. Don't give it a "bowl cut" which removes only the ends of the branches. But go all the way into the crown. It's likely you can find instructions & images with an online search.

the understock in the grafting process .... is grown for it aggressive roots ... and is upright ... and probably has a lesser flower and flowering pattern ... and.. it is not weeping.. so .. what they said ... get rid of it .. the white part i mean ... its more aggressive than the weeper.. and can take over the whole.. given enough decades ... ken

Ornamental cherries and the rest of the prunus family are subject to a host of insect pests, especially borers, and many other maladies. It's really pretty rare to see one as large as yours because of they are relatively short lived trees in addition to their other problems. A tree service company is probably your best course. Don't be surprised, though, if they recommend removal rather than treatment.

such a large tree.. was probably field grown ... and that looks like damage that began from digging it out of the field ... it may end up dying down to the ground... if it is a grafted plant ... most likely the graft is above the damage ... and you will end up with a root stock plant... and if that were a valuable plant.. they wouldnt have cut its head off for the pretty one .. im pretty sure... at this distance.. those are root suckers ... sorry to say.... but ..in tree time.. you might want to start over ... you could wait to see the show in spring.. and then decide... or find a better tree this fall .. and replace it.... dont go big again ... you might find a better.. smaller tree .. which for novices.. will end up easier to grow.... welcome to the forums .... below is a good primer on planting a tree .. do note.. timing.. and proper watering ... usually lawn irrigation is not good enough for a transplant ken https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub