Please add slow to singed q, reduced mana cost for w, add duration for w, and add more move speed.
Singed is supposed to be a running champion but right now most champion on the rift with all the dash, shield, and speed buff can outrun singed.
Roaming is not a great option too since nearly every champion can kill singed in one combo in early game.
Singed has a great deal of utility in his kit. He has grounding, slow, a niche root. He's also got his passive for speed buffs and his ult for overall buffs.
His kit isn't perfect - it's old as hell in a lot of areas and covered in band-aids to make it reasonably functional in the modern game, so he definitely is due for a VGU sooner than later.
The W / E interaction never felt good to me. With so many champions being so dashy its hard to do right. Not that I am in any way a singed main. Im just spitballing but maybe Singed Q could have a slow that gradually gets stronger and if you are in the poison long enough it roots you for a second and resets the slow. This way it really punished people dashing circles around you. W could be a burst of speed that also kind of vomits poison around you in a circle. and E could be just how it is, without the stun part. IDK but singed could use some more love for sure
Fun fact you can't outrun a Sylas. Even without boots
Rushes 
q slow
