I run https://formcrafts.com and http://formcraft-wp.com, and both are profitable, netting over 150k+ a year in total. They were my side projects when I was in accounting school, lol
We do get people using our site for phishing (perks of a freemium model), and, being a small fish, sometimes get the whole domain blocked. Working on the uBlock thing. They haven't replied back.
I am responsible for uBlock Origin (the other uBlock is abandonware), and I haven't received anything from you. In any case, my answer would have been that I am not responsible of the content of 3rd-party filter lists, and in the current case you would need to contact malwaredomains.com, they are the ones listing you as malware.
It's pretty hard to get traction through the plugin repository. I offer mine for sale at codecanyon.net. I feel the repository is good for utility plugins, but well-made, premium plugins should definitely be on a marketplace.
I sell a plugin on CodeCanyon as well. They get a big cut from the sale value and the marketplace could have been better but there's no better of its kind so I can't complain. I make around 400usd a month with very little effort.