He doesn't break any laws, hasn't been convicted of any assault charges, and his intention to keep the city safe are well meaning.

His mask isn't there to hide his identity, therefore he's not hiding behind it. It's constructed of stab resistant rubber (as is most of his suit), that makes it safety gear.

He's a civilian, and he works within the bounds of what civilians are allowed to do (what all of us are allowed to do) but that also means he's mostly on his own out there.
Not coming prepared for the worst when you look for trouble and can't depend on backup is a fool's game that can get a person killed.
And despite his bad grammar, he doesn't seem like a fool when it comes to self defense.

"Oh boo-hoo, he's rude" like it matters. His service is intervening trouble so that bystanders aren't dragged into a mess they're not equipped to safely handle. He's not being paid to be nice and make you happy. He's not being paid at all.
He doesn't owe you anything.

"He pepper sprays people" as if he should do something more heroic and less painful. No, he's just a citizen like any of us, and that's a non-lethal defense tool we're allowed to carry, and he uses it legally.

He dresses like a superhero, but really he's just an overzealous neighborhood watch.
Maybe he's just in it for glory, I dunno, and frankly I don't think it matters. He's a grown man. If he wants to live his life this way, he has the constitutional right to pursue happiness.

"A grown man running around in a costume should expect to be heckled, it's part of the position he puts himself in" No, that just makes you look disrespectful to others and intolerant of lifestyle choices.

Menace? No more than any other jerk of an ego driven tattle-tale in Seattle.