Is there a way to export all tv's of a site to XML or something so i can import them in another fresh install of modx?
I mean the TV definitions not the values.
You could use PhpMyAdmin to export the modx_site_tmplvars table to a .SQL file and import it into the new site (also with PhpMyAdmin). The TVs would then have to be connected to templates manually in the new site. They would have no values for specific resources, which sounds like what you want.