Sorry, but I think you are beating a dead horse. That's not because there aren't some nice features in XBMC or your imagination. It's that suggestion MC be like XBMC or your ultimate vision are far to vague to be of any possible use. When you (or anyone else) makes such suggestions, I can readily conclude MC is already much closer to my ultimate media manager than XBMC is or will likely ever be. I'm left wondering why you don't just use XBMC if you like it so much.
I've discussed some technical issues around the use of links to trailers—because I assumed that's what you were interested in. But it seems you're not interested in details. As a result, I've probably left the wrong impression. MC can actually handle trailer links very well. The Connected Media feature allows you to browse to any media site (like YouTube or HD-Trailers) and play, add the URL to the library or download any media. While I don't know how to find the correct form of URL for some of these sites, the developers obviously do. The issue I was trying to help you with is that you already have URL's, and you (nor I) know how to get them into the library so they can be played in Theatre View. That's not quite the same thing as "MC is unable to play trailers."
I think a more practical feature request would be a mechanism for handling and playing web links in Theatre View. I have no idea what is feasible, but it might make sense for the developers to consider this as they implement Chromium. We already have Links in Standard View, and they work fine for many different things—including links to trailers. It would be wonderful if we could, in Theatre View, browse to any web page associated with our media and, where applicable, play a web media resource—like a trailer.
Even if MC could handle your trailer links, it's not clear to me that would provide you with what you're expecting—the ability to play a high quality trailer for any movie on demand. Taking just a quick look, I can see TMDb is making a valiant effort to collect reliable links to the best available trailers. But that is still user-supplied data for something that tends to change—so they often don't work. There's often several links—sometimes to different sources, sometimes for different resolutions, occasionally both. If AutoMeta is getting all the links and MC were able to handle multiple links (i.e., try the "best" one first, the next if that fails), that would help, but this seems unlikely. So this might only provide the frustrating experience of often waiting for a minute for a two minute trailer to appear, only to see the request fail. Relying on a links implies there would be no opportunity to select an alternate trailer for the same movie.
Maybe I'm missing something, or the XBMC community has already dealt with all such issues and trailers work perfectly there. What I find very peculiar is for this sort of issue we never hear anything like, "I use XBMC, and it handles trailers flawlessly. Here's a link that explains how that's done." Either it doesn't, or no one here can be bothered to investigate fully and tell us about it.