I was hoping that may be with the dll of one of these plugins, you could have a quick whip at it (I don't have any programming language background and fiddling around can only get me this far...).
I have just tested these plugins with JRiver (on Win7 x64) but not with MSN Messenger. Please correct me if I'm wrong: I thought that if JRiver cannot recognize the plugin, how would another application be able to pull the output out of the player?
I do understand and respect your position about dedicating your time to players that are freely available and have a wider audience. After all, even for my layman's eyes, JRiver's API does not look like something that could be qualified as "insanely easy". On a side note, after a thorough search, I have not found (yet) its equivalent, but lo & behold: beauty is in the eyes of the beholder

. I would still admit though that one of the two areas that irks me a lot is the views manipulation of the otherwise very rich (too rich?) interface.
I'm continuting to research why the MSN interface doesn't work and if you find anything interesting (i.e. if you get an MSN interface-based plugin to work with anything) let me know
Certainly. I will continue exploring and will let you know if I find anything interesting.