I have the same hair issues as the OP. I haven't solved that (beyond a ponytail or braid(s)), but I also had the mask/hood leak problem, when I was wearing a hood in cold water. I tried the mask over and under the hood... still leaked! Finally I figured out that it was the chin part of the hood that was causing it. The reason was that it was changing the shape of my cheeks and that was causing my mask to not fit and to leak. I solved that by pulling the chin part under my chin (instead of over it as it was designed).
One way I handle post-dive tangles is to put conditioner in my hair before I shower (post dive), then I comb it out, and then shower/shampoo. I have heard of people putting conditioner in their hair before the dive, but I've also read that conditioner is bad for the reef, so I don't do it pre-dive.