While I agree that this shouldn't be abused, I'm not actually proposing this syntax; Arc already lets you say cut.x.1.3 as an alternative to (cut x 1 3).
I suspect that the only time I'd ever want to chain together several different things with . is when I'm doing list slices. Which is why I'd like the x.1.3 syntax to work, since in my opinion cut.x.1.3 is a lot uglier, perhaps enough that I'd rather not do it.