What we really need is our own reader for arc, so that ssyntax isn't limited to intra-symbol, but can be used between other tokens as well, such as lists and strings.
Can you help me understand why Racket's reader couldn't be extended to do this? It seems very extensible [1]. I've already gotten good mileage out of hacking it with aw's extend-readtable [2]. (Come to think of it, I should continue playing around with this to try and implement the JavaScript-style dot operator.)
I also wonder if rntz's arcc might be useful here [3]. (I haven't tried it yet.)