What you describe are all common. There are a few ways to increase root curl. If clipping and plopping didn't work for you you could try styling upside down.
As for the greasiness, I get that too. I use a leave in, but mostly on my length so that it doesn't add to the grease. Poo causes frizz for me, so I wash with water only instead and only use conditioner as a leave in.
2c/3a, F/M, ii, med porosity, good elasticity, APL, silvery dark brown.
Love coconut oil, olive oil, and Everyday Shea!