The funiest thing about this thread is : if we sum up everybody's comments, 32 characters are in the top 10. Maths and DOA can't go along well.
Every character has a hidden card in his sleeve to climb up the ladder.
So to reverse the flow, who is the last character?
I start the vote on kokoro: she's not so safe, she can't deal with sidestep gods, she's too easier to master with poor damage. Real fighters play with zillion inputs like 16545678923 PK that's not the case for kokoro who can poorly mix up K and P with one or two directions at most.
Well that's kinda the point of the discussion lol. Everyone has multiple picks for Top 10.
As for Kokoro, she may get outclassed by quite a bit of the cast but she's nowhere near the bottom. She's too much of an offensive beast and kicks too much ass to be near the bottom. Also, if you want to see what unsafe is like try playing a ninja like Kasumi, Phase-4 or Ayane (which you did make a mention of).
Check out some of these matches for a bit of a visual. Don't count Kokoro out!
@UncleKitchener Bass is also nowhere near the bottom.