If I had to design a phone right now I'd incorporate the best things I currently know. A lot of times there is only one way to do something then you add features too it. I'd make a list of my features to try to have them be better or as good as the best phone on the market (iPhone) like Samsung did. Almost seems dumb to do it any other way.
Personally I feel if Samsung was copying so badly then there would be no threads about iPhones users not being able to easily figure android out. If its a copy it would just be a large screen iPhone.
Ive only used touch wiz on a couple occasions but not once did I try to do something like I would on an iPhone. Aside from the obvious, phone, message, email etc which were around prior to either companies smartphones.
Another thing, if you are the best then you should have no fear of any competition. If someone copies you, big deal you are the best and that's the old way you did things. Now you do it even better. I think Samsung copied some silly things but now have surpassed that point. Apple is suing for the way Samsung did things with the galaxy s1? Ok, that's an old outdated phone. So what does that say for apple who still does things that way?