Great thread and advice! My hair sounds similar to yours, bosanbo. Except i have curls on the bottom layers and my top is struggling. What I have thought was frizzy/heat damaged hair on my top layers, sounds like your descriptions of over conditioned hair. I've been going in the heavy moisturizer direction to repair my damaged hair from coloring & straightening. Thanks so much!:-)
CG since 2011

Hair Type:
2b/c(top layer) 2c/3a (under layers)
Porosity: Low
Density: High
Width: Fine on top/Medium underneath

blonde hi-lights

Products & process:
(still figuring this out!!)

Trader Joe's Mint Tea Shampoo every 3/4 days
Trader Joe's Nourishing Conditioner
Deva One Condition LI or Shea Moisture LI
Herbal Essences Totally Twisted Curl Creame
Plop about 20 minutes
Clip roots
Air Dry

Lavender Mist as needed to revive curls
Pineapple at night