NO!
Do not ruin that bass with velocity. Hip-hop bass should always be compressed and almost velocityless to give it that undercurrent of rhythmic follow-through. I think what woulda been better was a changeup on the note during a 4 or 8 bar section of the main verse parts, maybe a jump in octave or a simple 3 note changeup every 4 bars in an 8 bar set, just enough to give it a feeling of bounce. As for the choirs, a little bit of smearing with some reverb to set them more in the middle rather than the foreground of the piece, and bring that whistle synth forward a bit with a tiny bit of compression and maybe some Send channel chorus lightly to give it more presence. It's a realy keystone to the track, which gives it character. The ambulance synth does fit the theme of the vocal sample, so that's a great idea.
Sorry for the wall of words, but this is a really good hip-hop track coming from an artist who is outside his comfort zone really by venturing into this genre. From all of the audio I've listened to from you, DnB and Classical seem to be your strong points, IMO, though the choir and strings here do fit right into that, but Hip-Hop is a rare entry in your audio. This was quite well done, if a bit underpowered for my tastes as far as the loudness of the track, but I compress and limit alot now so I'm sadly involved in the Loudness Wars...eh, whattayagonnado? Keep it up and definitely do more Hip-Hop.
Peace