I have stayed here 6 times in the last 3 or 4 years. A little too touristy and too many groups, but it is Hawaii.
1. As a Platinum I have always received nice rooms with great views without asking. Check in always gets me a nice "welcome back" and "thanks for being Platinum".
2. Correct on bus.
3. Correct on walking. Lot's of stuff.
4. Yes, there is a Hertz in the lobby. Suggest you book online though, for better rates. Limited hours open, but you can return car after-hours.