Can I use my main account If I am playing story mode games?

I am currently running ABadAvatar, I have xbGuard as well. I've recently filled up my library with a bunch of story based games like Saw and some Silent Hill. I want to play them, but is that safe to play while online?

I understand that my KV would be banned before anything else, but I wanted to see if I could use my main account. I would be playing legitimately and earning achievements. Should I just go offline and play and then unplug my usb afterwards and then go online to sync my achievements?

Ive heard some people say to never use main account, while ive seen some say its totally fine as long as I am playing legit and therefore giving no reason to flag anything or giving anyone a reason to report me.

Just looking for some closure, thanks in advance!