Is there a way to predefine the row height, column width and font in saved search results (not columns) so that when it is exported as Excel file, the formats will flow through?

I don't think so, as of now. You could do it in an Advanced PDF template and associate that with the Saved Search but that would be in PDF format not in Excel format.. Alternatively if you use Workbooks you could adjust the column width and height but I'm not sure if it can be exported to excel. It's a mess..