What characters from previous games would you say are unsafe?
Hmm... for veterans I'd argue that "unsafe" characters have at least 2 of following characteristics in most peoples' eyes:
1. Have doubts cast on them because of things said in interviews. (eg; Snake, Ice Climbers, Pokemon Trainer)
2. Have doubts cast on them because they share similarities with previously cut characters (eg; Lucas, Wolf, Ike)
3. Have doubts cast on them because of only being in one game (Brawl's newcomers)
4. Have doubts cast on them because of relevancy (eg; Sheik, Ike, Pokemon Trainer)
5. Have doubts cast on them because of things shown/said in the pics of the day (eg; Shiek)
These are all debatable, of course, especially with how much they actually mean in the grand scheme of things or even at all. For example, the Ice Climbers are a great example of this. Sakurai mentioned complications in programming them way back in August but now we have Rosalina who is argued to be much more complicated as a character. Another example is Ike. Despite not starring in a game in roughly 6 years, he's still a very popular character and even heavily referenced in Awakening. Yet another example is Lucas in category 2. 5 of the 6 characters cut in Brawl could be described as "clones" but will this same standard be used in SSB4, especially with Toon Link already making the cut? Just some food for thought.