1) It expands the the size of your inventory.
For questions 2-4, use this.
for a whipper base.
Playful Schoolgirl: 10th from left and 2nd from top
Icy 1st place: 4th from the left, 3 down.
Bloomers: 1st column, 3rd one down.
for a SW base.
Playful Schoolgirl: Top row 4th from the left
Icy 1st Place: 13th from the left, top row.
Bloomers: Bottom row, 12th from the left.