There's one thing about the recent developments that has been bugging me for quite a while, namely this part of chapter 517: http://www.mangareader.net/bleach/517/19
The way I see it, she's saying that the lock was much easier to break into now, compared to when "she was there", i.e. compared to when she was in charge of the laboratory.
But during TRPA, we saw that Kisuke was the one who founded the R&D department. Furthermore, he told Mayuri that if anything were to happen to him, Mayuri would be the one to take over R&D since he'd be the Vice-President. So, where does Shutara come in?
PS: I realise that it hasn't been confirmed that Mayuri took over from Kisuke (or at least, I don't remember it having been confirmed), but I'm pretty sure that the youngest member of the RG is Kirio, who was promotod during TRPA. I doubt they'd recruit two people in such short succession.
Well, it could have been up back in that time, then shut down for dangerous researches carried out there.
Shutara probably was the mad scientist of his (her?) generation, but I can't really say anything about the ties with Mayuri. Though I'm more or less sure that it was because of that relationship Mayuri was deemed dangerous and got locked up in the Maggot's Nest.
Well, the previous captain of the 12th division was kirio hikifune who also invented some stuff which the shinigami have use for. Perhaps before urahara founded the research department the 12th division was already kinda part timing into research for stuff. With urahara they simply created a specialized research and data analysis area to formalize where research would be conducted in the future. Of course before the divisions were founded any sort of research would have been conducted at random by whatever shinigami who cared to look into something.
Yeah that could be it. After given it some more thought, I realised that she could simply have meant when she used to use that room for research and not to her being in charge of R&D.