We were staying at RPR for the 4th this year. Since my mom was with us and she is unable to be out in crowds, we stayed at the hotel for the fireworks. We had a great view from our room in Tower 1. My mom also said she could see them from her suite in Tower 3--even though she had been told she would not be able to see them. I talked to a guy the next day who said he was able to see the fireworks from his float in the RPR pool.
I am told the fireworks are not as wide spread after the 4th. We may have been able to see more of the fireworks if we were at CityWalk...but I had heard about huge crowds and being unable to get back to the hotel for an hour, etc. I would do it again in terms of viewing the 4th of July fireworks from my room at RPR. Oh, BTW, I think we saw some of the Disney fireworks off in the distance as well!
Oh--the park crowds are bearable during the day on the 4th. Of course you will have FOTL, so that will make it that much more bearable.