Sub-Sub-Blogs — creating and importing content into a custom sub-type

Description:

The university radio station I volunteer at uses WordPress 3’s Network Mode for the entirety of its web content. It uses the format:

• Top-Level (.com/*) — Basic station
  information, links to feeds, etc. The
  main site.
• Subdomains (*.domain.com) —
  Station departments (I.e., “music”,
  “spoken word”, etc.)
• Program Top-Level Sub-Directory
  (.com/program/*) — Custom post
  type (“Program”) for individual
  shows airing on the station. Locally-written proprietary code.

Most producers have existing social media property (Facebook/Twitter/MySpace/Soundcloud/Tumblr, to name but a few), and we’re wanting to encourage producers who don’t currently use social media to start using it. To this end, I need two facilities — a blog system and a RSS importer.

Questions:

1. Blog system — Users should be able to post directly to the WP system, but be restricted to individual program categories. I can probably figure out the first part with roles, but is there any way to restrict where a particular user is able to post? I’ve also thought about doing this as another custom content type so as to keep it separate from the main station posts system, but it might be difficult to get an RSS importer plugin (See below.) to work with this.

2. RSS importer — I don’t want to force users to use the station’s WP system if they’re already using other social media tools. Because most social media tools worth their salt produce RSS feeds, I figure the easiest way to accomplish this is via a RSS importer. I’ve used feedwordpress in the past, but I worry it’ll be both too confusing and too powerful for the users I want to access it. Think this is simple enough I could code it from scratch, or is there a particular plugin I should use?

Thank you!