Workaround: create a custom input behavior class and manually handle the navigation when holding the Shift key
public partial class SpreadsheetForm : Telerik.WinControls.UI.RadForm
{
    public SpreadsheetForm()
    {
        InitializeComponent();

        FieldInfo behaviorFi = typeof(RadSpreadsheetElement).GetField("inputHandler", BindingFlags.Instance | BindingFlags.NonPublic);
        behaviorFi.SetValue(this.radSpreadsheet1.SpreadsheetElement, new CustomSpreadsheetInputBehavior(this.radSpreadsheet1.SpreadsheetElement));
    }
}

public class CustomSpreadsheetInputBehavior : SpreadsheetInputBehavior
{
    public CustomSpreadsheetInputBehavior(RadSpreadsheetElement element)
    : base(element) { }

    public override void ProcessKeyDown(KeyEventArgs e)
    {
        base.ProcessKeyDown(e);

        if (e.Shift)
        {
            switch (e.KeyCode)
            {
                case Keys.Left:
                    this.Spreadsheet.ActiveWorksheetEditor.Commands.UpdateActiveSelectionRangeCommand.Execute(MovementType.MoveToPreviousColumn);
                    break;
                case Keys.Up:
                    this.Spreadsheet.ActiveWorksheetEditor.Commands.UpdateActiveSelectionRangeCommand.Execute(MovementType.MoveToPreviousRow);
                    break;
                case Keys.Right:
                    this.Spreadsheet.ActiveWorksheetEditor.Commands.UpdateActiveSelectionRangeCommand.Execute(MovementType.MoveToNextColumn);
                    break;
                case Keys.Down:
                    this.Spreadsheet.ActiveWorksheetEditor.Commands.UpdateActiveSelectionRangeCommand.Execute(MovementType.MoveToNextRow);
                    break;
            }
        }
    }
}

The control can be resized in the designer.  The resize operation starts with a slight delay and it is necessary to wait for this initial delay. From then on the control can be freely resized. The attached gif file illustrates this.

Workaround:
1. Set the size using the property grid
2. Add a panel and dock the control to fill the panel, then resize the panel

Ideally we should expose the events in the RadPrintDocument object.

Workaround handling the PrintPreview method:
private void button1_Click(object sender, EventArgs e)
{
    RadPrintDocument printDocument = new RadPrintDocument();
    IPrintable printManager = typeof(RadSpreadsheetElement).GetProperty("PrintManager", BindingFlags.Instance | BindingFlags.NonPublic).GetValue(this.radSpreadsheet1.SpreadsheetElement) as IPrintable;
    printDocument.AssociatedObject = printManager;

    printDocument.BeginPrint += PrintDocument_BeginPrint;
    printDocument.PrintPage += PrintDocument_PrintPage;
    printDocument.EndPrint += PrintDocument_EndPrint;
    printDocument.QueryPageSettings += PrintDocument_QueryPageSettings;
    SpreadsheetPrintPreviewDialog printPreviewDialog = new SpreadsheetPrintPreviewDialog(printDocument);
    printPreviewDialog.ThemeName = this.radSpreadsheet1.ThemeName;
    printPreviewDialog.ShowDialog();
}

private void PrintDocument_QueryPageSettings(object sender, System.Drawing.Printing.QueryPageSettingsEventArgs e)
{
    
}

private void PrintDocument_EndPrint(object sender, System.Drawing.Printing.PrintEventArgs e)
{
    
}

private void PrintDocument_BeginPrint(object sender, System.Drawing.Printing.PrintEventArgs e)
{
    
}

private void PrintDocument_PrintPage(object sender, System.Drawing.Printing.PrintPageEventArgs e)
{
}

How to reproduce: check the attached project and the remaining memory after disposing the forms.