I might suggest using YAML too, either as an alternative or as a complete replacement. YAML (when written in a certain way) is basically JSON without any line noise, and optimized for human reading and writing. You will be able to parse it exactly the same.
In regards to the nesting level: what do you mean? There shouldn't be any technical limit on the nesting depth.
As for escaping special characters: I've run into that a lot, and I agree it is very annoying. God help you if you want to specify regexes on lines.
So for a lot of my YAML-ish applications, where YAML is used for user templating or configuration, I run everything through a really simple postprocessor (often by encapsulating non-digit lines with single quotes, and a few other tweaks) and that seems to work well for me. That way the user only has to type the bare minimum (no double quotes, no curly braces, no/fewer commas), and what they write "just works."
