Reasons 2 and 3 are pretty legitimate. Into Darkness was absolutely terrible (though most of the blame for that goes to those ubiquitous garbage mongering hacks Kurtzman and Orci). And Harrison Ford has been phoning in his performances for decades now. Since there is every indication that Han will have the largest role to play out of all the OT characters in this film, that could well be a problem.
As for reason 4 - That's really more a reason to rein in expectations than to expect objectivey bad quality from this film per se. Nobody should be blindly walking into this thing like we did back in 1999. Fool me thrice, shame on George Lucas; fool me four times, shame on me.
Reason 1 is no reason at all as far as I'm concerned. By the looks of the teaser trailer, JJ Abrams is not feeling himself overly obliged to slavishly reproduce the visual style of 1977-1983. And as for the rest of the film's elements, particularly plot, story structure, editing etc. I sincerely hope it doesn't work for modern audiences, inasmuch as utterly worthless brain-melting shit like the Transformers movies apparently do "work" for modern audiences. A film that takes its cues from great movies of yesterday, and paces itself with some intelligence and deliberateness rather than striving to meet a Michael Bay-like quota of explosions and mind-numbing action at the expense of story is one that is aces in my book. Gareth Edwards' delightfully restrained Godzilla, though it has its flaws, is proof that a less-is-more approach is every bit as viable today as it was three decades ago.