This site (http://www.yvr.ca/en/passengers/navi...ssenger-guides) might be useful; hit the left dropdown and select I am ... Connecting From Canada to a US city.

Make sure the bag is checked through to HNL and you will not need to pick it up in YVR. Actually, I never recall having to pick up bags in YVR going Domestic->YVR->US. Enjoy your freedom when you land in YVR!

If you're laying over on a weekday, you will pay $4 each way for the train, or you can pay $9.75 for a day pass. In either case, you will pay a $5 surcharge purchasing at the airport.

Also CBP has given me grief when I was in the "connecting" line when my origin was YVR. There is a possibility of grief if you show up in the originating line but have a connecting boarding pass. But you should be fine. Your story will make a lot more sense: "Just wanted to go into the city during this long connection"