Any missable skill points?

[MadEdders95]

So I know getting all the skill points is not necessary to getting the plat, but I do like to get all of them without too much hassle. Are any skill points missable, and are any recommended to do before challenge mode? Thanks! 

[adamska_br]

If you're going to finish challenge mode anyway, then really you can wait to do any of the missing ones. None of them is missable, however. Even any of the combat ones can be done with ease on challenge mode as you can change the difficulty at any time (there's a skill point for completing the hardest arena challenge without being hit, for instance).