If you're not going to do these it's not going to sound real at all, realistic performance is all about the details. automation will make things sound much more realistic.
2 other things, attacks of choir and strings are way slow and make them sound unnatural too. regular humanization of velocities and where the notes actually fall on the beat will help with a real sound.
this song is really lacking bass in general too, you have a low string part but it's not very present.