Some suggestions:

- option to select individual results of "Search nearby places" or select top N closest result to your location

- collapsible criteria on the edit/view pages

- automatically name name untitled heatmaps. I have a ton of "Untitled Heatmaps" in my history which I forgot to name

- combine the edit/view pages - just have an edit page with a big "Generate" button so you can still edit criteria after heatmap generation