Ok, pretty good post but I feel the need to point some things out:
Up B: Very useful move. It can be used as a spike, although a bit more difficult to use than her down b. Since it draws the opponent back it is useful for pillaring with combination with her down smash. Also useful for racking up damage when someone is on a platform above you. Another combo move, albeit being difficult to pull off, is after you've used your second Up air, use her Up b and then use Bair or Fair.
D aerial: Not useful as an approach from above because of what you stated and its low priority.
Good luck with the combos. The great thing about Zero Suit Samus is that she is one of the most combo heavy characters in the game.