Learn English – Synonym for “raise the bar”

When you don't know how to use your firearm, you become a menace.

As used here, menace is a noun meaning:

A person or thing that is likely to cause harm; a threat or danger

You use irksome of something that irks you.
You use pestering of something that pesters you.

Both irk and pester refer to some irritation of their objects
(which must be human or at least capable of emotion), but they have different connotations.

Pester refers to repeated episodes of being irritated (usually by something or someone).
Irk simply means being irritated (ditto), with no reference to history or repetition.