You are worrying too much. As indicated in your tripadvisor thread, you will be covered by ANA. I suggest you post on ANA forum re. how they handle misconnects due to immigration delays.

Not having checked bags is not likely to affect the connection because the bags come out just fine. It's the long immigration lines.

(Compare that at YVR where AC guarantees the connection even if you get delayed at immigration/customs - I once spent 3 hrs there and after the thorough inspection the officer said AC would rebook me.)