hippocrates
Next time it hangs, open activity monitor and see if anything is "Not responding". I bet you will see a safari web object as the culprit. Under my safari prefs, I have unticked "use plug-ins" and "allow-webGL".
I also managed to find a copy of Safari 10 on the web and when it begins to play up, usually after an update, I simply re-install it again. I agree it is a fairly "sensitive" browser now.