See you later.
As a designer, you should already know that people will reshare your content, redesign it, etc (with or without credit regardless of what you want, its unfortunate but that's how things are). You don't see Adobe quitting because someone made a similar software to theirs that looks the same, or because someone cracked it. (Photoshop for example https://www.photopea.com/). The review system works as intended as well - your image will be judged based on how you deal with upset "customers" or in this case the members of this community who use your mods aka your reviews could drop on all your products based on how you handle a situation.
I assume you reported those violations to the staff members? If so, did you provide any evidence that you made those skins/mods? Just because something looks the same it doesn't mean that it's your property.
The LSPDFR dev team are pretty generous too that they don't charge us for the mod. Kind of shitty that you're talking shit about the time that it takes and you bring up charging people out of nowhere. Yes, it does take a while and I think we can all agree that we wish that it was faster but it is what it is.
I personally haven't witnessed any staff members treating members poorly they might be assertive though.
As for members being ugly to each other... I guess welcome to the Internet? There is nothing that you can really do about that. Some people will always be rude.
Just my two cents though.