Well to be fair, he's kind of a plain guy with seemingly low self confidence, and she's a very pretty former idol beloved by many. Even if it seems like it should be obvious that she's interested in him, a guy like him is going to doubt that it could be a possibility. Although, even if he did immediately shoot the thought down, he did for a moment consider the scenario of him being a love interest.
I feel like this would be so much better if she just confessed first chapter and they started dating. Because I'm really not remotely sure on what this "progression" is meant to be.
I was once invited by my Japanese coworker to go to a maid cafe while we were on a business trip in Tokyo (right in Akihabara). But I remember someone saying that the food is not really that great while being costly.
Can't say anything about maids. I'm neutral about it. But if we're talking favorites, I'd say Toki from Blue Archive.