Okay, that helps clarify. Let me try to help in return.
1. Yes, the pricing you are seeing is the standard pricing for United saver award flights from North America to Hawaii. Standard domestic is 12.5K each way in economy, 25K in (domestic) first; Hawaii is 20K in economy, 40K in first.
2. This may or may not be a "good" use of miles. Check the fare for a $ ticket. I can't tell whether you are looking at doing one direction in F because you want it, or because Y isn't available. If it's the latter, and you don't care about flying in F, then you should compare the 60K miles you'll use to whatever you would pay for a ticket in Y. If it's only $600, then I'd buy the ticket instead. If it's $1200, then this is a pretty good use of miles. Keep in mind that 60-65K miles will get you a round trip to Europe or Asia with a stopover... if you're into that sort of thing.
3. The goal is to get yourself to your destination as comfortably as possible. Flyertalkers sometimes get obsessed with optimizing the onboard experience ("I got SQ first class!!!") at the cost of other factors ("but I leave at 3am with connections in Moscow and Ethiopia..."). Domestic F is certainly better than Y, but a good itinerary (no early morning departure, convenient connections, etc) can be worth more. Optimize around YOUR personal preferences.
4. That said, there is a big difference between standard domestic F recliner seats and the lie-flat international product that UA flies to Hawaii from certain hubs. I believe EWR, IAD, and IAH to/from HNL are consistently operated with BusinessFirst seats. If I was going to pay the premium for a domestic F award, I would try to get one of those flights.
5. The 777 service from SFO is occasionally operated by an international plane with lie-flat seats in business class, and you can also book the true First cabin n those flights for 50K miles. There are a couple of posts on blogs about how to book 3-cabin first from NYC to HNL by booking the P.S. flight from JFK to SFO and connecting to a 3-class 777 from SFO-HNL. If you have specific dates, this is unlikely to work for you (unless you get lucky).
6. Since you aren't trying to do anything complicated like a stopover, you can just book separate one-way tix for each direction. So if you don't want to fly Unitd both ways, you don't have to -- you could book United one way and American the other, for example -- and there is no mileage penalty for booking one-ways.