25. Yes, but centrebacks don't need attacking skills and wingers don't need defensive skills. Also, with the new version, it has become much easier to improve skills in the required field.
26. IMO no.
27. It can work with short passes, but with high press no.
28. Not necessary. My ace striker is terrific from freekicks.
29. Not necessarily. Look at Spurs.
30. I feel it does influence, but I prefer to give new players 2-3 consecutive starts.