Are they really shouting "oi" during "You're the Only One"? It sounds like it. Though it's meant to be an acoustic song, dragging out an acoustic guitar is often impractical and I used to do it this way, turning the volume on the guitar to around 4 till the heavy rock kicks in. (I still do it this way.)
In my experience, the crowd response to such quiet interludes (and to any kind of dynamic pacing, really) can go either way, that is, they dig it for its own sake or they're put off by any hint of "diversity". Slow, acoustic, quiet, etc: not "punk". And ya gotta be: "punk." Maybe the punk can be restored by chanting "oi oi oi" during it, which is always worth a try. (And, as I've said before, the first solo acoustic tunes to appear on an MTX record -- "Even Hitler..." and "Will You Still Love Me?" -- were greeted with shock, horror, and cries of "sell out" in some quarters: "like Dylan goes electric in reverse," as one pretty famous guy once put it.)
Among those not super concerned with punk policing, though, this song has always been rather beloved, often requested, quoted in yearbooks, etc.
There was one show (at Coney Island High in New York, I think, '96-ish) where this great big fat drunk galunk in the crowd had been throwing his weight around, so to speak, for most of the set, knocking over the littler people and just basically being an obnoxious jerk while stopping just short of doing anything so particularly egregious as to get himself kicked out. This was a common thing at such shows and still can be even now that everyone's all old. By the time it came to "You're the Only One", though, he finally went too far and trampled his way to the front of the stage, knocking over the mic and interrupting the song. Well, it's a short song, and it didn't seem worth resuming it, so I said something like "well, anyway.." and got ready to move on to the next song. Then I got to see a 280 pound guy beat up and stomped into the ground by around a dozen little girls, who then insisted the song be played from the beginning. Now that's my kinda security detail. I love my people: you can only push them so far.
About "I Fell for You," I've recently revealed minor secrets in a previous post:
Anyhow this is the thirteenth and fourteenth out of sixteen songs on that set. I'll post penultimate one next week, God willing.