That permission is there because I have a share button- if you click it a popup will open where you can choose to post the app to your wall.
You have a point though- I will see if I can split the permissions such that I only request wall posts after you choose the share option.
EDIT: fixed, I took out the wall publishing permissions and the share button still works. Enjoy!
The one suggestion I'd make is to see what you can do as far as adding more to the location markers. Ideally, something that IDs my friends without requiring me to click would be best. Maybe incorporating tiny profile images, or names (maybe truncated). I know it could get crowded pretty quickly so it would be something to experiment with for sure.
(p.s. thanks for the feedback!)
Are you able to reserve a space outside of the map that is dedicated to displaying friend thumbnails? You could update that section with new thumbnails when the mouse hovers over one of the nav markers. It would prevent the pop up/map position adjustment from being necessary.