I wouldn't consider mirror mode any safer than stealth injection - it's hard to form any conclusions about which client is more dangerous, and likely the difference is negligible. I personally use stealth injection for everything as it is most resource efficient and quicker to set up, but it comes down to preference. Here's a good thread on the topic which is worth a read if you haven't already seen it: https://osbot.org/forum/topic/124429-preventing-rs-botting-bans-v3/
2: Yep, should work for addy, bronze, iron etc.
3: I cannot think of any further data you could gather, but thank you for offering. I'll have a chat with the other scripters and see if anyone else is having this issue, to determine whether or not the developers are already aware.
Cheers