I do not want to post on a page, but the user should be able to automatically post in his stream.
Posting in a user's stream is done with Open Graph Actions, not with the Channels feature. Channels are for admins to push content to their own promotional pages, like Facebook Pages, Twitter Streams, or LinkedIn Company Pages that you own.
With Open Graph Actions, an 'action' can be posted automatically or manually to a user's Activity Log. Automatic actions, like "I read an article" have much less weight since it's automatic, while if you choose to create a button that the user explicitly clicks, like "I cooked a recipe", it will show more prominently in their Timeline.
So, with that said, you shouldn't be asking for the manage_pages permission since it sounds like you want to post in the user's own timeline, not a specific Facebook Page, correct?
If that's the case, can you explain a little more about the other site you have working and what it's actually doing? I'm a bit confused if you're using Channels on the other site to post into a user's own Timeline, which isn't what they are meant to do...
If the error in using the https protocol are?
Your site does not require an SSL certificate in order to post content back to Facebook.
Thanks,
Alex