What properties should I set?

[Bertalan Fodor]

Hello,

advanced LilyPond users could help me. I'm writing a "tweaking wizard" for
the LilyPond plugin for jEdit. That means that the user can choose a context
and the plugin will tell him the context properties that make sense.
My question is:

for example in the ChordNames context. In the doc I find the properties of
the engravers and I find the translator properties that are given a default
value. Is that all that should be set?

Another example: it is well-known that in a Staff context I can set the
midiInstrument property, but I can not find it out from the
internals-documentation. I look at dynamic_performer, I found it, and found
it also in Tunable-context-properties. But how can I figure out that setting
midiInstrument makes sense in (and only in?) a Staff context?

Please let me understand the structure.

Thanks,

Bert