Nope, just accuracy. 

Mine is fast and as much accuracy as possible to land the debuffs.

Do  you  know  why  some  debuffs  won't  land  if  the  hit  is  weak?  

and  why  doesn't  that  apply  with  Uugo?  

It does apply, but i dont understand why that means you would want crit rate?

As far as i understand it, with negative affinity you have a 35% chance of a weak hit and it isnt affected by the champs crit rate.

oh!  I  always  thought  that  more  Crit  rate  elevates  the  chance  for  a  hit  to  be  normal  or  strong....  So  to  avoid  weak  hits,  champs  need  crit  rate...  That's  what  where  I  was  getting  the  idea  that  champs  need  crit  rate  to  land  debuffs... 

Weak hits cannot be critical. So, when you are on weak affinity, not only do you have a 15% penalty to critical hit, you ALSO have a 35% chance to weak hit.

That essentially combines to mean even if you have 100% crit rate, you'll only land a critical hit 56% of the time.