1) The current version of the plugin saves the location data in the custom fields below:
so all you need is to echo get_post_meta with any of the fields above.
However, the new coming version of GEO my WP will not save the location in custom field anymore. But it provides a simple function/shortcode that will allow you display any or all of the location field of a post.
If you are planning to update to the new coming version I can provide you with the beta version ( pretty stable ) of it and will show you how to display the field with the new short code or function.
2) The Shortcode for displaying map of a single post also changed a bit in the new version. So depend on your answer if you want to try the new version or not I will explain you the short code.
3) You can read a bit about custom template files here. Please take a look and if you need more help let me know.
If you do want to try the new version send me an email to firstname.lastname@example.org
Also (if you do not mind of course ), posting questions directly on GEO my WP support forum is easier for me to track and I am more responsive there.