You did not make a mistake with the ms8, unless you listen to nothing but techno. Look up the definitions of tonality, imaging and staging, and ask yourself if those things are important to you. To most people they are.
Regarding door speakers, just get the Focals. The price is right. Those cost over $600 over here! Like I said you can change the tweeters later on if you don't like them.
Don't be stressed out, it'll all be worth it in the end.