Hey There,
I´m new here and need help. How can I extract the pure coordinates (lon/lat) for all country-coastal-and land borders?(a code to see witch coordinate I have to line to a other would be helpful too)
I knew that the borders are the Administrative level 2.
But how to get they for the whole world, and only with about 500 - 1000 Points per country definition?
Properly the best output format will be XML.
I would be really thankful for any help. 
Greetings
Killerlort
I cannot give you a direct answer about country borders for the whole planet, only some ideas:
Instead of using XAPI of OSM, try http://wiki.openstreetmap.org/wiki/Overpass_API … but I do not know whether that web service is able to give all borders with admin_level=2 to you from the wholew planet.
Otherwise, download the whole OSM planat data from a suitable mirror and do some filtering with http://wiki.openstreetmap.org/wiki/Osmfilter
OR:
use data from http://www.naturalearthdata.com