I should probably throw out this comment:
Deva does not work for everyone.
Yes, I said it.
Yes, the Deva cut has brought great things to the curly world, but I know plenty of curlies who would never touch a Deva product because it makes them dry, frizzy, etc. There is no magical line that works for everyone.
For most, it takes a certain amount of experimentation. In your case, have you examined your hair for its likes and dislikes? Its porosity? Thickness?
Finding the ingredients that make or break your hair means a lot. In my case, I'm relatively sure a keratin smoothing treatment would not particularly help me, considering that a) transitioning sucked for me and b) when my curls are looser, they're really stringy and refuse to clump, which gives me the appearance of frizz and dryness.
Don't get me wrong, keratin treatments are fine for a lot of different people. But in your case, I get the feeling that you don't know your hair that well, and that lack of knowledge my harm your hair in the long run when it comes to just about any treatment. For example, a keratin treatment will not magically make your dryness disappear.
For the record, I wouldn't be too intimidated by curl types and such. They don't matter as much as porosity and thickness (both density and of the size of a strand). Yes, on some days it's frustrating (I remember years of my life that I hated my natural hair and cried every time my grandmother detangled it---she did not know curly hair, having stick-straight hair herself), but I think in the end, it's been worth it, embracing a part of me.
Hair Type: 3c, Med-High Density, Low Porosity
CG since '09
Low Poo: KC Come Clean
Condish: AOHR, TN (Avocado), TJ Balancing Moisture
Leave in: GDL, KBB
Curl Lotion/Gel: CHS/CK
Others: CJ Curl Rehab, Jojoba Oil