Alphonse is pretty soft for an 8. I'm not sure where the first spot Julie is talking about is, I think there's only heading into the notch after the overhang. And the hanging belay isn't a hanging belay if you set up in just the right spot (which is all the way to the left). By the way, wthout doubles, it can't really be done in one pitch without unpleasant rope drag - I say this from unpleasant experience.
The gear on Birdland is impeccable. There's no reason not to make this an early lead in one's 5.8 career. Ditto for Eastertime Too, except that the gear is definitely hard to get in. Some people skip it, and that's a big mistake. But if you hang in there and get it (or even if you fall trying) it's quite safe.
I don't know if Farewell To Arms is R or not, but I can say that there are some 5.8 moves where you really don't want to fall. Baskerville (which is rated 5.7+) as well gets PG13 in the Swain book, and I agree with that. You'd bang yourself up pretty good if you fell at the end of the crux sequence. Very puzzling crux, by the way, hence very satisfying when you finally pull it.
Main Line is a great climb, but there are some issues with the gear that make it less than ideal for an early 5.8 leader.
We haven't mentioned Outer Space, by the way. There's a couple of PG spots, but the climbing there is way below 5.8. A good early lead.
5.8 is a great grade at the Gunks, but not as much in the Nears as in the Trapps, where there are tons of great pitches, many of them fine for someone breaking into the grade.