The bathrooms and Flash were separate buildings... while I don't have inside info, I seriously doubt Flash was removed for bathrooms.
I rode it about 7 times today during the media event, from back to front and in-between. IMO, it's a fun, fast, solid, reridable coaster. Will it crack any enthusiast's Top 10 list? Unlikely... there's not really anything super distinguishable about it. Will it probably be a hit with the GP? I think so.
Same sort of thing happened with FT. Enthusiasts weren't/aren't super impressed, but the GP can't get enough of it.
One credit I do have to give it is some of the headchopper effects on the final leg are insane. On the first overbanked airtime hill (again, on the final leg), you could swear you could reach out and touch another section of track.
I also did enjoy the fact the park got female first responders to be the guests of the first "official" ride.
Side note--because of the recent cell phone incident on TC, they were very adamant about making sure pockets were empty, and put in lockers just before boarding. They were free today, but probably won't be once it opens. The ride does have a small zipper pouch like FT and WCR, but they were being pretty strict about leaving phones in the lockers. Glasses with a strap seemed to be okay. It'll be interesting to see how this policy will affect wait times once fully open.
And the ultimately, the building that's going up will become retail and a common exit to both WW and Batman.