I tend to use a left hand pluck for the second note of that 'roll'. Kinda lazy, but whatever works...
When I learned the tune this puzzled me, too. The arpeggio sign (not explained on page 8 of the book) indicates a brush.
In the second half of this bar two this sign is missing so maybe the f# should be played with a hammer-on.
If I understand you correctly... that sounds awkward to me. But not sure I know where you mean exactly.
Here's a nice video of Rhiannon Giddens playing it, though for some reason it's mirror-image. She just brushes those arpeggios, which was always what I have done if I'm in that tuning.
I always found circus jig a touch difficult till I started forcing my thumb to play the part as described. I used to play with a pull off but I generally play it as a brush now because I'm lazy haha