Raku

Dark Road will lead into th3 beginning of BBS. What if we get to see how Terra & Aqua meet too.

a time travelling vanitas?

What Ocean's Rage said. And it would be cool if we got to see a young Yen Sid!

no, brain was the one whos name was circled in red and ven is the only one whos name wasnt on the list

Everything I've seen and read so far is making me want this DLC more and more. I wonder if KHUx 's updates are gonna start rolling out faster to coincide with the DLC's release? To be completely honest, the Bosses and the new scenarios and cutscenes are already enough for me, I mean who knows what kind of cliff-hanger we're in for... Mirage Arena-ish world would be cool, but i'm kinda hoping they incorporate a new area for the new stuff like Cavern of Remembrance, with high level baddies and tricky platforming.

To be fair, STR traits are still worthwhile, but only the +1000 and +2000 traits. Anything lower than that (which comes from pet training) is worthless. It's a good idea to mix the ground/aerial def traits with STR traits, as well as Extra Attack traits (and raid traits if you plan to use the medal for raiding).
DEF traits are the least useful, with HP traits being a close second.

Nomura responding to a question about Xion's return by saying he will expand upon it in the DLC doesn't indicate she will be the central focus.  I think it's more likely we'll be getting the final mix treatment.  Limit Cut" sounds like it might mean Director's Cut, which would be additional scenes throughout the main story to flesh out the plot a bit more. 
 
We need more backstory on Scala, Xehanort, Eraqus, and their Master more than anything imo.  Seeing as it is the end of Xehanort's arc, and everyone else's subplots can be explained in future games.  This is it for Xehanort's story.

Well, the events right now have prizes that aren't extremely necessary, so don't beat yourself up too much if you can't complete them. The expert level stuff usually requires extremely good medals with very specific traits. If you don't have ground def -60, for example, you won't do much against a lv. 5000 enemy. The reason for that is because your strength has to overpower their defense, and the only ways to do that are to have a high strength stat (primarily from your supernova medals), use all available buffs/debuffs (atk up for you, def down for them), and have either ground/air def -60 (depending on which type you're facing). If you're able to hit all of those points, it's hard to say why you wouldn't be completing the events.
As for setup advice, you'll usually want to use Starlight, Stroke of Midnight, or Fairy Stars (make sure they're at or around lv. 35). Your buffer goes in the first slot, preferably something like SN KH3 Kairi or SN Xion. After that you'll want to follow up with damage-dealing medals that make up for any buffs/debuffs you haven't already covered (for example, the 2 I mentioned only do +12 PSM atk). You don't have to match your buffer medal to the slot multiplier (you don't have to put a power medal in a power slot, in other words), but you want to try and make sure all of your damage-dealing medals do match the keyblade slots. Your most powerful medal should go in your pet slot as that is the highest multiplier on any keyblade you use. Oh, and make sure you have a high subslot value (using those 7-star medals you mentioned).

Hmm, I'm not familiar enough with ux lore