Wisconsin Weeping Willow Tree

Willows are water-loving trees and do not favor drought conditions.

The wisconsin weeping willow prefers wettish areas, and does not to be too close to other trees

No, but you should rely on an expert for your area if you are concerned. From my experience, they are super shallow. They are all around orchards and the roots run horizontal with the ground. Also, from what I have researched, they are shallow roots that run along the surface of the ground. If you water them plenty, the roots will not need to go deep to search for water.

I have very wet, very heavy clay and my Willows that are growing best are the ones right smack in the middle of it. Go figure.

We have these planted in sunny and wet locations and they do quite well.

Deer might try to rub their antlers on any convenient young, pliable trees, but willows aren't specifically known for "attracting" deer. If deer are problematic in your area, I suggest putting up fencing around any young trees planted there.

I would not suggest it.
I have a few that I purchased from Stark Brothers that I have planted down near my pond in the wetlands here in Oregon.
I was putting in a drain line from the house down to the pond the other day and this is a approximately 15 foot tall 5 inch in diameter weeping willow and I was digging about ten feet away and hit some small Roots all the way out there. General rule of thumb is for every 2 inches it grows in height The Roots grow 1 inch.A willows roots grow around everything.

The wisconsin weeping willow grows about 3 feet per year.

It covers 3.5 to 9.0.

Weeping Willow trees like this one bloom with small, yellowish flowers/catkins in the spring, but they are far less showy than the fuzzy flowers/catkins of the Pussy Willow (Salix caprea).