The dangerous look alike I've found are same as what you have described, amanita that haven't opened yet, but if you slice them down the middle you should see the Beginnings of their skirts and gills.
I don't see other look alikes in my area, but I'm not sure about other areas! I have found the more I get out and get hands on experience with foraging and identifying, the more comfortable I get with the area and what grows here.
Have fun collecting and identifying! Even if you don't eat them, it's still a blast!