III) An unknown moderator deleted 7 of my posts on 27 and 31 October 2018 on my main English scam thread and on my Italian thread. I wrote to HostFat about it, but he denied being responsible and wrote he didn't know who it was.
They were not deleted by HostFat. You were multi-posting.
IV) On 27 March, HostFat removed all the posts about my case, including several of mine, from the Rock Trading main italian thread, which is entitled precisely Rock Trading "discussions and problems", where the Rock CFO were posting lies about my case, and transferred them to my thread on the much less known and read italian scam board, effectively "cleaning" the most exposed and important italian thread about the Rock (70% of their customers are Italian) from the negative publicity about this issue:
https://bitcointalk.org/index.php?topic=330856.msg50341791#msg50341791As far as I can tell, this appears to be within the realm of reasonable mod discretion regarding what's derailing a topic and what's not. The posts still exist, and HostFat mentioned them in the topic. HostFat denies any connection to The Rock Trading which would constitute a conflict of interest. (The ref link is very minor.)
Discussions about whether or not it was ideal for the topic to be split in this way would best take place in the Italian section, since it's impossible for someone who doesn't speak the language to get a feel for the flow of the conversation.
Again, on the same post, he raised suspicions on me
On the same day, HostFat posted allegations against JollyGood and suggested that I had paid him
He posted allegations on my italian scam thread that not even the Rock CFO dared to post,
First of all, you can see there is a signature, part of which states "The Rock Trading (ref): A good exchange since 2007."
These are not mod actions. He is entitled to his own opinions on the matter.
(Personally, from what I've read, I find The Rock Trading's behavior highly questionable. But it's debatable, especially when all of the details aren't known.)
I see nothing surprising here as this kind of behavior constitutes the very definition of the person behind the alias HostFat. It always did.
HostFat has moderated the Italian section for over 7 years, and I can recall few complaints and no unethical actions. I think that you're biased against him because of his support of BCH, and while I strongly disagree with him on that, I haven't seen any mod abuse related to this from him.