You can send a message to a user by clicking on their name (which takes you to their user page), then by clicking on send message. Simple.

You can send a message to a user by clicking on their name (which takes you to their user page), then by clicking on send message. Simple.

Hi, I really cannot help you further. I despise Google and thus will not even try to understand how their map stuff works. You should find examples about setting markers in the OpenLayers documentation if you decide to go that route.