To set the height of a row, you would use code like
grid.Model.RowHeights[row] = 40;
To show 2 fonts in 1 cell, in 1.6, you can set the cell style's CellType to "RichText", and use richtext to show the mixed fonts. See the Syncfusion\Essential Suite\Grid\Samples\CellTypes\RichTextCells sample.
Or, you could handle the grid's DrawCell event, and use calls to e.Graphics.DrawString to draw the strings in different fonts.
Or, you could derive a cell control that did DrawString at the cell level in the derived renderer class's Draw method.