Hi Mike,
I've generally had it return to the dialog window as you have stated, although its a bit long winded I tend to use the results window to access previous dialogs. The only option I know of for keeping things in view on error is the option to keep the background geoprocessing messages up if an error occurs.
I'm not aware of anywhere this property can be set for the dialog.
Prob worth noting if you write the scripts as python toolboxes you will need to restart catalog or map as the tools are loaded on startup only not after each edit. Think you can get around this using the python reload built in but have not tried it yet.
Dave