Each problem shows a set of coins, drawn at their real relative sizes, and the student adds up the total. The coins are a genuine mix - not the smallest number of coins that makes the amount - so a student has to look at each one rather than assume the biggest coins first.
The dime is drawn smaller than the nickel and the penny, because it is, and that is one of the things this exercise is for. Turn coins on and off under Coins, and set Amounts if you want the totals kept under a dollar.
Pennies, nickels, dimes and quarters by default. Add the half dollar and the dollar coin under Coins if your students have seen them.
Because a real handful of change is not. A page of "three quarters" teaches a student to grab the big coins and guess; a real mix makes them count.
Between two and eight. More than that is adding practice rather than coin practice, and it does not fit the row.
Yes. The coins are line drawings labelled with their value, sized so a dime and a quarter are clearly different even with no colour.