We are redoing an old bath and are eliminating a separate tiled shower and moving the shower into the bathtub. The contractor says is no big deal. However, what needs to be done to close off drain and plumbing before tile over floor? Does this need to be inspected?

Additionally, the tub is smack next to a window, so will have to use a curved shower curtain. Easily doable but will this create a problem if inspected?