I'll answer your other points one by one.

1. Perhaps you'd also like to opine that Germany's evil Green Party warmongers would eagerly support any other communist purge that might happen in the future?

No, I think they'd wring their hands and do nothing. They might demand that the killings be carried out in an ecologically sustainable way.

2. Unlike Glorious Great Britain and their United States of Amnesia puppet-masters?

The Greens would fall into line quick smart, just as they have done in the last twelve months of incessant war-mongering by Britain and the U.S.

3. on the subject of communist purges - d'you have anything critical at all to say about Stalin's 1936-1938 Great Purge

I certainly do. I recommend Donald Rayfield's magisterial study of the purges: Stalin and His Hangmen: An Authoritative Portrait of a Tyrant and Those Who Served Him (Viking, 2004)

I took notes on the whole book, and I will post them up in the near future, now that we're on this topic. But these passages give something of the flavour of the book:

157 SHOW TRIALS. Stalin needed a judge and prosecutors able to give credibility to his kangaroo court. Vyshinsky and Krylenko were just the ticket. On any scale of odiousness Vyshinsky ranks high among Stalin’s hangmen. “Confession is the queen of evidence”, he said. He bullied into mute submission defendants he knew to be innocent of trumped-up charges. ...

159 The Soviet public was not yet ready to applaud witnesses like the 12 y.o. boy who demanded his accused father be shot.... Five old bankers were condemned to die. Mandelstam, last keeper of the public conscience, protested, and they were spared. Nobody emulated Mandelstam however. Civic courage in the USSR was dead, and Mandelstam was regarded as mad.