However, when you’re editing the page defaults and add a block, you can click on it again and you’ll see a menu entry which allows you to set up the block on existing pages as well.
Open it and you’ll see a list of all pages from the same type, mark those where you’d like to place the block and you’re done.

So what exactly default is I dont know and no one has be any to match their description with what it actually does. (same as composer)

There are some patches in the forums that allow you to specify the block types allowed in an area but as far as I know they never made it into the core.

The only thing you can do out of the box is to use the “advanced permission mode”. Check this site: http://www.concrete5.org/documentation/general-topics/simple-permissions/ There’s a line you have to insert in site/config.php to enable it.

But be careful: The advanced permission mode gives you a lot of power and increases the complexity as well. Just give it a try, you can always remove the line and go back to the basic permission mode if you don’t want to use the advanced settings.

I defiened a block slideshow on every page using the Page Type method, I also limited the number of Blocks to one (using setBlockLimit), but someone is still able to add more than one block (through deleting and re-adding) as well as blocks of an other type.

is ist possible to prohibit the deleting of the block but still allow to change it (i.e. change the pictures by an other user, not admin).

< ?php define('PERMISSIONS_MODEL', 'advanced'); ?>

ENGLISH:
How to implement a Blocktype (for example “slideshow”) in a pagetype of a theme permanently which is still customizable (assortment of pictures)?