I am not sure about Ash being part Sull, I not saying its not true I just have doubts, primarily due to the fact that Mal and Ark had to drain her blood and give her fresh Sull blood, which indirectly indicate to me that she had no Sull in her bloodlines, or it could mean she was like a trenchlander and needed purification.
One time I asked JVJ point blank in an email if Ash was Jack and Tarissa's daughter and she told me that she couldnt tell me that, but that there were red herrings in place, so with that comment in mind I think it is possible that we have some surprises in store for us. The boots could have been Angus's (he seems quite familiar with that gate), the babe could have been Raif, or possibly Bram Cormac, both are of the right age.
In regards to predictions I think that the Unmade will find a way past the blindwall and begin their conquest.
