I do have some constructive things to improve RP. I remember ingame seeing someone say to you with wide eyes "Are you a guard?!" To which you replied with "No, but I know some."
I know if that had been me, I would have entirely stopped caring (all ICly, ofc) about what you are saying as soon as "No" came from your lips. And to be honest, I can't see there being any problem with you saying you're a guard--because you are. In every sense of the word, you're just not an Octarchal guard.
All, in all, your RP, IMO, would drive home much better if you could simply say, "Yup, I'm a guard so sit down and stfu". But then, you should probably run that over with the GMs, so they don't banzor you for impersonation \o/