The accents are completely true to style, I agree. I wouldn't say your attempt at Mozart was a complete failure, but you chose a piece of music that sounds much simpler than it is. There is a lot of tradition in playing Mozart and none of it is captured by a sample library. You have to put that (the accents, and phrasing) in yourself. But perhaps Strauss comes more naturally to you, because when you start such a piece you need a certain "feel" for the sound you want to (re)create. You have to make the translation from note to sound as a player would, only this time for all instruments. So it's not surprising some of it comes easier, some harder. But while doing, you learn and discover, so who knows?
I made a lot of disastrous tests before finding the right sound of Strauss' music on computer. If today I'm able to rebuild his music, I have studied for more than a year his music and also my sequencer (Logic) and my libraries. Today I can rebuild almost any of his pieces on computer.
So, as it took me a long time to get Strauss' spirit, I guess it will take also a long time to get Mozart's spirit.
I really like your recreations, this one included. Having listened to a lot of your music, I thought maybe the reverb was a tad too saturated on this rendering ... it may have muddied all that great plucking .