About the back of your hair getting puffy: What I think may be happening is two things: The first is that you might have a curl pattern like mine, where you have your tightest curls at the back of your head. The second is that your new growth is probably really starting to come in. So what I'm thinking is that when your hair had all the chemicals (and/ or flat iron heat damage) in it, your tighter curl pattern may have been somewhat "dampened" because of that.

So if your hair is starting to grow out and get stronger, you may have reached a critical length in the back where your tighter curls are coming in and therefore are starting to show their tighter pattern than the rest of your hair. This is normal and good. It's the process of your strong new curls returning to you. What I'd suggest is putting more conditioner back there, and making smaller curl units to define in that area. Or I'd suggest spending more time running your fingers through multiple times in that area (if you aren't defining your curls individually). When you run your fingers through, sort of press your fingers together as your hair is running through your fingers to help "bind" your curls together. Or even try defining your curls just in that area. The thing with tighter curls is that they often need to be defined in smaller units than looser curls. I'm thinking your different textures may be beginning to show, which means that the tighter curls will need more defining than looser curls on the rest of your head.

Also, as your hair grows out, you may notice that all your hair begins to puff up more. This will be because a stronger curl pattern will probably begin to come in now that your curls aren't being squelched by heat or chemicals. So you will begin to see and experience them at full strength. This is why I do recommend defining your curls, because for me, running my fingers through my hair defines it a little bit, but I find there to still be puffiness if I only spend a couple minutes running my fingers through. Only by taking the time to define my curls have I found them to stay puff-free. So this may become true for you as well. Also, it depends on what kind of conditioner you are leaving in, and how much of it you are using. Oh! A compromise may be to simply divide your hair into sections (like, say, six sections) and go through your hair section by section and run your fingers through each section several times.