the options you shared relate to when you get notified of things including getting a PM, notification could be within BL or via email.
if you go to the privacy section to can also configure who is allowed to send you PMs, there you can pick from BL members, people you follow, or nobody - hopefully that give you what you need.
if "having trouble" means that you're being harassed that's just not acceptable, hopefully you've reported it if that's the case, Admin will have other tools to see who the users are, IP address, location etc. Don't stand for that shit!