3a curls do tend to get stringier/wavier as they get longer, but if your hair is fine, then you may need protein. IAgirl has a protein treatment recipe in the protein-craving forum. Oh, and do whatever you think is best for your hair! If you think it looks better long, then keep it long; if it looks better with layers, then layer it! Good luck!
Curly and PROUD!!!

My hair has a mix of low/med/high porosity, and it's medium textured (some are still fine, though!)

CG since Sept. 2011
Cowash: Vo5/Suave Naturals/Tresemme Naturals*
RO/LI: GVPCB*, Tresemme Naturals*
Low-poo: Shea Moisture Moisture Retention
Stylers: KCKT*, Coconut Oil, Olive Oil, Grapeseed Oil, Honey*

* represents my HGs!!! Finally!!!