This part also tripped me up. Tried to break it down and grasp it structurally:
Summary
要はだね = “What’s important / The point of (the concert is to warm people’s hearts)”
この町の人のみみがいいか = “Are the people in this town’s ears good [enough to appreciate our music]?”
ってところだが = This one got a bit wonky for me, and I feel like I’m still futzing with the interpretation
- って (speaking of)
- ところ (place)
- だが (but/however/yet)
- So trying to slap the above together: This may not be such a place (where people can appreciate our music)
In one sentence: “We had intended to warm people’s hearts (with a concert). Whether or not the people of this town have an ear for that music… We doubt that’s the case.”
I think your reading of はなはだ心配だがね is the right one.
For なにしろぬけとるようだから:
なにしろ = in any case, because, however, you see
ぬけ = omission, fault, slip
とる = to pick up, to take
よう = seems, form, like
だから = because, therefore
“You see, it’s because (the people in this town) seem to make mistakes.” or “The people in in this town seem quite incompetent.”
I suppose it’s appropriate that snooty artists will use this kind of vague, subtextual language? Can’t say I recall such passive-aggressive dialogue in the book before.
That was a surprising minefield of grammar and syntax I attempted to wade through, so please correct any mistakes I made.