I'll second the recommendation for Nootropics Depot. They're top notch with regard to testing (they run an ISO 17025 accreddited lab), and the owner frequently talks about the science of how various compounds work and interact on r/NootropicsDepot.
Yes, around 13k currently. Startup is slow, but I keep it open so that doesn't matter much. With Zotero 6, speed isn't great for general usage, but workable. Zotero 7 (beta) however feels very fast. I've switched to it already -- most plugins haven't been upgraded yet, but (at least currently) you can switch between v6 and 7 since there's no database updates involved.
You say "this hasn't happened" and "plenty of oversight", but the president of the review committee just resigned because of this. And she isn't allowed to inform the public nor parliament of what has already been happening, even before this change. As in, examples of the type of surveillance already happening have been redacted from the annual report of the review committee [0]. The annual report was specifically made to omit operational details and only inform of the general picture, but parts have been declared state secret. The now ex-president of the review committee stated she could not inform parliament because she did not want to go to prison for 15 years [1].
Hmm, I've had only one experience but it was positive. Last year I had a CrowdSupply order fulfilled via Mouser, it arrived reasonably fast and there was no hassle with customs (I'm in EU).
