Earthbound is basically Dragon Quest in a goofier, modern-day setting. I like it more than any Dragon Quest game, but at heart it still shares a lot of Dragon Quest's flaws. I largely agree with your review, save for two aspects: Jeff's not entirely worthless, as in the late game he finally gets reusable items like the Bazooka (which bumps him to Useful, albeit still the second-worst damage dealer in your group), and Paula shouldn't die very often because of how the health roller works.
In fact, the latter is something of a complaint for me: once you're past the Blue Valley, it becomes pretty hard to die from damage, as you generally have enough time to prevent anyone from reaching zero health. By contrast, the hardest parts are the early game, when it's just Ness, and Magicant, when it's once again up to Ness to solo the thing.
Personally, I'd bump the score up to somewhere between 7.5 and 8, just because of how goofy it was willing to be, but there are certainly better JRPGs out there. AND it's much better than its GBA sequel. I'm glad it's finally available for purchase, though, as it's not a bad game by any stretch.