That isn’t 45 degrees, and the grass will easily absorb 2 inches of water. You just can’t expand the paved patio and will have to keep the grass in good shape so the soil doesn’t dry out and compact.
I have a less dramatically sloped yard, though away from the house, and the bottom doesn’t get any more soggy than the top. The ability of soil to absorb water is huge.
Looks like it has its initial owners from 1993, which also suggests the house isn’t a lemon.
I think if you like it, you should buy it before someone else does. Inventory in the area is close to zero.
