digital deluxe content?

Can anyone clarify what's included in the deluxe upgrade besides the new skin and future movie-themed stages and a skin?

I assume the BGM pack provides additional music to play in-game, but what about the skill points? Are they for an increased limit on the number of skills you can have, or just in-game currency to purchase more skills?

Additionally, what won't you receive if you buy the content after starting a new game? I've seen a warning stating that certain aspects might not work unless you start a fresh save.