So, first off you put some time into this idea, and I like it. Speccing should be just like watching TV, you should be enjoying it and awing at the players instead of floating around and being bored. This sounds similar to a mod for Quake (3?) or HL(?) that makes speccing like viewing TV, showing the players in different angles and making it more exciting then it really is. This would be great for scrims or practices whereas people who are waiting for the game to end are just being bored then leaves the server.
Now, that being said, this mod is not necessary, but so is TremX or Arcade but we still want those mods to be available to us (Well, some of us). For those who takes this mod seriously and blab out "THIS MOD IS BAD BANHAMMER 4 1.2 GAY IDEA KTHXBAI" I see it as more of a novelty and pleasure to have, like a Hud, something that you can enjoy having for convince and I don't see Urc suggestion to implement this into v1.2 or any other client/mod/etc. Keep in mind to give the player options of viewing the game like CS, in case I either want to see some crazy angles flying about or I want to view the player for reasons like aim-bot checking, skill observing, etc.
As for how difficult it is to code, it sounds tricky but I don't see how it could be that difficult (That being said without any coding expericne), but for the more complex ideas you put up if the coder wants the mod to be smarter, it sounds difficult.
Well, I like it, I don't see how this mod is bad, so I give it a thumbs up. The only problem is if this mod is going to be coded and how well the camera could handle tight spots or crazy interactions between the two teams in battle.