I think R.O.B. and G&W and ZSS should go down, and Lucario and Peach should go up.
G&W is very easy to deal with if you are patient and don't run into any smashes. R.O.B. is kind of the same way in that you just have to be patient and camp him back. ZSS is hard if you don't know the matchup, but in my opinion it's just a matter of knowing all of her limitations. I actually think she is really good, which is why I play her, but I don't think she should be as high as she is.
Maybe it's just because I play peach and I'm not excellent at killing, but it just infuriates me how well Lucario can camp and how little he has to do to just shut down a lot of characters. The opinion that Peach should move up is a bit biased, but she definitely deserves a boost, especially with all of the new techs that Peach players have been finding. How many non-peaches even know that she has a guaranteed Uair string that can do anywhere from 20-100% on everyone in the cast, and that she can walk while she pulls turnips with the c stick (which helps her camping and overall mobility greatly)?