There’s a bug in the messaging system that will count spam in the rate, even if marked. Which is why most people reply with a simple “no” before reporting/blocking.
In theory, yes, though CS is overwhelmed currently, and it’s easier to just bring your rate back up by replying to more messages.
For me, it depends on the file type. I have my computer set to display previews without opening files. No clue now much that helps, though. I never open suspicious stuff, unless the client has already placed an order, and I’ve run a check on my computer.
Yes, but it’s not very good.