A set of ideas for improving the strategic gameplay.

1, 2, 7, 8, 12, 14, 15, 17, 18 - not needed (0 out of 10).
9 and 16 - need to be carefully considered (5 out of 10)
The rest - 3, 4, 5, 6, 10, 11, 13, 19 - needed (10 out of 10).