I agree. We don't like epcot fireworks FP area either. Much better places along the lagoon to view it.
Rivers of Light FP area is good, but I don't think it's that difficult to get into the show without FP. And once it's near showtime, if the FP area is not filled up they let standby people into the FP area. We've gotten ROL FP day-of as a 4th FP.
Fantasmic is in a stadium-like setting with bench seats, so you don't get in, you can't see the show. ROL is similar, although there are a few spots around the area where you can kinda see from bridges (those wouldn't be great viewing IMO). If we want to see Fantasmic, we just make sure to arrive early to get in.
Fireworks at MK, epcot and Star Wars fireworks/Jingle Bell Jingle Jam at HS you can just walk up and find your own spot. The castle hub area does fill up with tons of people for Happily Ever After, so that's one that you'll want to show up early for to get a good spot with an unobstructed view of the castle.