I think you are mostly correct...

About SSS, you can fake it but it doesnt look nearly as nice as real SSS. Mainly cause SSS is a complex phenomenon which you cant easily duplicate with fakes. A great example is something as common as milk. There is no fake method that can successfully give you the look of real milk. Not even mentalray's SSS shaders are able to do it easily.

Also you cant do proper caustics with refraction alone. Take a look at this:

http://www.motiondesign.biz/vol_start.html

There is no way to simulate those scenes with refraction alone, and they are all very common situations in real life.