Your setup is all over the place. Lets refer to the visual overview here:

http://codex.wordpress.org/Template_Hierarchy#Visual_Overview

Your page is going to use the page.php template.

Your custom post type weine will use single-weine.php

Your custom taxonomy sorte ( probably not the best name as it might clash ) will use the template taxonomy-sorte.php

So we can expect by default to have a weine post with the title “example” to live at:

example.com/weine/example

and the sorte taxonomy term ‘examplesorte’ will have its archive at:

example.com/sorte/examplesorte

What I expect you’re trying to do is change it so that there is no /weine/, or you think that by using postname that it will change the link of ‘weine’ posts. This is incorrect, and while there is code out there that may change this, I strongly recommend against this as it introduces dangerous permalink clashes. It’s also better if you use the weine URL structure to your advantage.

e.g. I would recommend modifying the rewrite base of the sorte taxonomy to use weine/sorte as it’s base, giving you URLs such as:

example.com/weine/sorte/examplesorte

A Note On Flushing Rewrites

You need to flush them when your custom post types and taxonomies change, but never do it on admin_init or init. Regenerating rewrite rules is slow and expensive, and by putting it on those hooks, you’re massively slowing down your site, and introducing potential bugs and problems.

I would also kill trying to set custom post types parents as that of a normal page. Use the slug in the rewrite base but go no further than that.