Currently I'm using namesilo as a registrar, and my own domain for email, albeit with G Suite.

I hope that with G Suite you won't get kicked out arbitrarily, but I think I could still recover from that. Hopefully the registrar will never need email confirmation to log in (assuming my DNS setup is there).

Still, I'm worried that could get me kicked out of my registrar illegitimately. Is there anything that can be done to mitigate this aside from using something super expensive like MarkMonitor?

Earlier my account at namesilo got disabled silently when they decided by themselves that my corporate credit card was somehow fraudulently used by me. I got it resolved eventually, but I fear something similar could eventually lock me out completely.