"Neutralised" bugs me, but it's probably because I'm from America.
Previous Special Containment Procedures:
I feel like if you crossed out "Euclid" in the classification, you should do the same here. Rather than having what were the previous procedures, instead have the containment procedures struck through and put the current one at the bottom of it. However, I don't think the same should apply to the description.
SCP-XXXX was capable of relocating to any tank in a public aquarium or store selling aquarium fish in the country of the United Kingdom…
Why only the United Kingdom? Is it the distance between countries? Is it the ocean? I need more clarification. Also, how are they able to relocate?
SCP-XXXX-2 instances would begin to doubt their current romantic relationship (if they were in one), and experience relationship problems. The relationship would gradually deteriorate until one of the partners ended it.
And if they weren't in a relationship? What would happen then?
Overall…I don't know. I feel like this draft is situated between "not having enough" and "definitely good enough". It has potential, of that I can say. The SCPs and Addendums are fine (save for the nitpick I had above), but the description needs more to it. I can't say exactly, but when reading it, I felt like I missed out on an important detail or two.
If it came out now: Neutral vote.