Your comments

Raina, could you confirm:
(1) Your friend is not yet a Roam7 user. 
(2) You said yes to all the Facebook permission Roam7 asked for when you first signed in.
Thanks.
This is a bug. We're looking into it. Thanks for the heads-up!
Hi Raina, thanks for the question. If more than one story is tagged to the exact same location. You'll be able to see only one story (in the form of a thumbnail) on the map. To see the the other stories from the same location, you can click on the orange location link wherever it appears (e.g. in the story that you can see on the map), or you can search for that location in the search bar. 
In this particular case - i.e. someone who's not your Facebook friend comments on your story in Roam7. If the corresponding album on Facebook is open to all, you'll see the comment on Facebook. If the album is open to friends only, the comment will not appear on your Facebook, it will just appear on Roam7.
We hear ya, we'll be prioritizing privacy settings.
Hi Christian, I'm afraid currently you'll need to have a Facebook account to use Roam7. One of the main reasons is that Roam7 is a lot more useful when you and your friends are on it and logging in with your Facebook account lets us know who your friends are.
We do plan to support other mechanisms in the future and I started a thread on that:

http://support.roam7.com/topic/117171-let-non-facebook-users-sign-in/

Please vote for it and let us know your requirements. 

1. Privacy setting is already a requested feature: http://support.roam7.com/topic/116507-privacy-setting-for-stories/
Please vote for it and let us know of specific requirements if any. 
2. Yes, we do have a way of selecting and prioritizing stories based on your relationship with the story owner and the stories' popularity so that the map doesn't become too cluttered. In effect, everyone will see a personalized selection.
3. Yes, being overlapped could be a reason. If you zoom in enough and the points separate you should be able to see your stories. At a higher level, they  may be hidden due to #2 above.
For now, all stories are publicly accessible by default. We do plan to add privacy controls. Please let us know how important/urgent this feature is to you. 
We hear you, Raghu. The issue is that the photo looks like it's a modal (aka lightbox) over the map when in reality it's actually a page by itself. So that's why there isn't a "close" button. We will redesign the page to remove this confusion. 
We hear you, Raghu. The issue is the photo looks like it's a modal (aka lightbox) over the map where in reality it's actually a page by itself. So that's why there isn't a "close" button. We will redesign the page to remove this confusion.