How can I get MySQL workbench to always show the result grid?

Here's one way you can do it. Pin the results tab to force it to remain and be unaffected by UPDATE statements. Do that by right-clicking the result tab and choose "Pin Tab" from the context-menu, or left-click the little pin icon to toggle it. Now, execute your other queries and then refresh the pinned tab (there's a "refresh" icon in the result grid's menu).