I had another request from a client today about this. Any thoughts about this?

I'm not sure I follow your concern on the file/image browser. It seems to have that support built in. On the home page it shows that example. You can also create custom buttons with this, so you could actually use the same dialog that you currently use as an image/file upload attribute type as a button in the RTE.

First, I think having under site settings/social the ability to set up one (or more) pages/accounts. Then under user setup, you can restrict what users have the ability to post to social from what apps.

The actual posting process would be on creation and/or updates. I could see it being an automatic thing with new blog posts/calendar events. After creation, you could have a tab for managing the event: being able to post replies or even repost the link to your wall. Having the ability to change the status message for each posting would be great. I could also see it as an enabled dialog box after the first save to really draw your attention to the process.

I see this being heavily used with blog and calendar. I could see it as a request for real estate/rental (new listing, price lowered, etc.), store (new products, sales), campaigns (lnik to the archived campaign page).

Personally, for a couple of the church websites I manage, creating events in multiple locations is just time consuming. Being able to stop creating events manually on facebook would be great. Likewise, when posting a new blog post, it would be great to just publish to website and send directly to facebook.

Yes, I think it being tied to an admin account is good. The only concern is when there are content managers, so user A might have written the post but user B actually posts it to the website. Having the person be able to override their own personal account to post as another person would be a must for my use.