Thanks for the reply Wontolla! 
So "off notes" are badly timed notes to you? Do you have example of a song where it's done correctly and it could have screwed the song if it wasn't? Or vice versa maybe.
there's no personality in your melody.
Wontolla might be suggesting you need some more of you in your creation. Something a little more human.
It really sounds the same.
are you playing your melodies?
One way to control your notes, is the length of them, rather than the start.
I tend to quantize a good bit of my musical, but i only do that for the start of triggers(midi notes). Just to make sure they're on top of the beat.
My attack from the synth/drum machine/sampler allows a slight time difference so my transients aren't all on top of each other.
I find it better to adjust the sound with the synth than to do it on the sequencer. (don't over think this, it's just a volume/filter envelop thing)
You need to consider how the sound is being made from all angles, and how you best can control the sound you're after with the tools that are available with your understanding.