SN is completely legal. There are some restrictions around
selling it, but not buying or importing.
You should definitely expect a welfare check after buying SN and having it shipped to the UK. I remember there were posts about it, it's a pretty common practice there
No, you shouldn't.
Welfare checks in general are unlikely, police resources are stretched thin and it's hard enough to tell that someone has even
received SN.
I did not get a welfare check and most people will not.
The most likely scenario to get a welfare check is if the police somehow get the list of DMC's customers, as happened with KL in Canada.
Awful news for me. I'm well known to the mental health services and even have a criminal record so I'm completely fucked then it seems. Might have to reconsider
Don't worry about it. The chances of the police showing up are very small, regardless of you being "known to the mental health service".
If they
do show up then you just have to deny having an intention of killing yourself and refuse to let them in. You can, of course, agree to engage with them, but you have the right not to.