Question 1: The statement is correct. The sides angles of the four sides of squares is the same at 90' but for a rhombus, the angles pairs up and will end up with 2 different angles. In other words, it can be a "Slanted square"
Question 4: No. I think that the statement is wrong. A parallelogram might be a square but a parallelogram need not be a square, a rectangle is a parallelogram but it isn't a square.
Question 5: A parallelogram is something which has opposite sides and the opposites sides are supposed to be parallel and BFED fulfill all the above requirements to be a parallelogram.