Thank you for any input. All experiences with this are welcome!

One would think that using proxies actually increase ban rates, rather than decreases. My experiences come from several years of professional sysadmin duties and I would say that determining which connections are tunneled through data center is fairly easy, just by looking who owns the IP.

I am not saying that using proxies makes 0 sense - as they make it harder to chain ban accounts.

When it comes to RuneScape ban rates in general, I am not entitled to answer that question. Sorry.

No one can give you an estimate due to a multitude of variations. However it depends on activities you do and money making methods. 

generally data center proxies increase banrates. Their purpose is to unchain accounts, that means, to avoid chainbans by botting from the same IP. I'd stay off proxies unless you're running 3+ bots

Expanding on the variation of activities depending on whether you bot for 1hr to 12hrs, run high banrate activities such as runecrafting and click intensive lengthy bots, poorly written scripts, or flagged proxy ips. All this and more plays a part. Depending on how long you want to go flag free you must account for everything even how many people run the script. Little things like manual breaks from botting for clue scrolls for example help, along with interacting with people that could be potential reporters

Does anyone know if automatically dismissing randomz everytime or ignoring them leads to more scrutiny on an account?

I have added human touch to the bots and they survive a little more with proxies, if you make a chain of repetitive events, if you don't chat, you don't trade, so don't missclick, that counts in the proxies and it's easier to detect a bot with proxie