allow registered users to publish without approval by admin

I want to allow registered users (default joomla user group) to publish content to some certain categories without the need to be approved by an admin.
I tried hard to set up permissions in order to allow this but with no success. So it dawned on me that this may not be possible in general since in J 1.5 registered users are not allowed to publish by default.
Is it -in general- possible to auto publish content which is written by the registered users group to specific flexicontent categories without that an admin has to approve the content first?

you use FLEXIaccess?
your users need to be at least publishers, but FLEXIaccess does not allow more permissions for user than what their Joomla groups gives them

-- Choice 1:
You make all users (default user group for new registered user) to be "Publishers" and then limit their permissions via FLEXIaccess allowing publishing in only a few categories

-- Choice 2:
Create 2 frontend: "new item submit" Joomla menu items,
First item will have auto-publish enabled and submission in specific categories
Second item will not have auto-publish and all submission in other categories

I think choice 2 sounds more reasonable (somehow I don't like the idea to elevate 2000 users to publisher state...) but I'm afraid I don't understand it.
Could you pls explain how choice 2 would work if joomla itself doesn't allow the 'registered users' group to publish?

Simply FLEXIcontent code decides what permissions to check

so if you use a FLEXIcontent menu item FLEXIcontent will load and USE/CHECK menu item configuration instead of user publish (edit.state) permission

Strange: This is exactly what I did.
I use a flexicontent article submit form (FLEXIcontent » Items / Form)to let registered users submit their content. The menu item is configured as in the screenshot:
www.picpaste.de/G3c8xws7.PNG
The categories, where the content has to be submitted to, are set up that registered users may submit, edit, publish and delete OWN articles:
www.picpaste.de/d6fd4dfe218cc904b06c71a9693fef73.PNG .
But every time when a registered user posts something through this menu item the article is not published but it has status "Pending Approval - Unpublished".
Can you tell me which setting I'm missing?

If you have an older custom form override,
then it will not work

your form is missing a hidden form field that declare menu item to use,

this is checked by store procedure