ColWidthToTwips, RowHeightToTwips, TwipsToColWidth, and TwipsToRowHeight, as any methods that use twips, are not handled the same in .NET. For sizes, the .NET products use pixels.
var text = new FarPoint.Win.Spread.CellType.TextCellType();
text.FocusPosition = FarPoint.Win.Spread.CellType.EditorFocusCursorPosition.SelectAll;
fpSpread1.ActiveSheet.DefaultStyle.CellType = text;