The pimples of higher ground can be hit with your pickaxe. One light hit and then you can flatten better. I wouldn't use the new pick for that though unless tested somewhere unimportant. The pick actually works well anywhere you start to get the visible gray cliff looking areas, even if not very tall.
But one thing to do is not try to make huge area of flat ground for building, terracing is a good option and makes things look more interesting too. If you have your buildings on different levels with gardens out farther away you can take advantage of good views and safety from troll attacks. Their logs don't hurt living plants, unlike pigs...