Warning: urlencode() expects parameter 1 to be string, array given in and not getting the preffered output

First of all, never use query_posts. Rather use WP_Query to construct your custom query which is the prefered way

You are also using the category_name parameter wrong. If you look at the WP_Query documentation, it states

category_name (string) – use category slug (NOT name).

Go and have a look at the examples given in the docomentation under the category parameters

EDIT

You need to do someting like this

'category_name' => 'SLUG OF Breaking News Stories, SLUG OF Call-out, SLUG OF Featured Story, SLUG OF Standard Stories'