Cuz if it's the timing isn't right... then practice along with Slash note for note, vibrato for vibrato, tone for tone til anyone who's listening can't tell there are two guitarists playing.
If you want to innovate in his style, I'd suggest redoing his phrases and make many variations on his themes in the modes and scales he uses on the progressions he plays against. Break it down! Don't just imitate. Write it out. Use your music theory to help or even other artists. What are Slash's influences? How deep are you willing to dig? Then integrate it in your playing.
It sounds like you want people to know you pay tribute to Slash just from hearing you but you also want to be your own artist and stand out too. If that's the case, do both of what I suggested above. If not, what's the real problem. You have the chops and drive... this will only be a matter of time for you. That's my thought.