@plusch I don't think it's a good idea to manually put stuff in Pd/extra. What's your OS? Don't you have a Documents/Pd/externals folder? Usually deken creates this folder for you, or something along these lines. It's better to put things in your user environment rather than in your system environment.
I don't know about the chaos library. Is it a collection of objects (many .c and .pd_linux, .d_fat, or .dll files, according to your operating system) or is it one monolithic library with one .c file and one executable? In the case of the latter you'll have to import the library, e.g. [declare -path /path/to/chaos -lib chaos].

@jaffasplaffa I second that.

It seems that the cyclone developers assume that you put the cyclone folder in Pd/externals without putting the cyclone folder in Pd's search path, and then load the objects with the cyclone prefix as it is with the objects of this library in their help patches. I actually agree with this approach as it is easy to figure out which library an external belongs to.
Try removing the cyclone folder from Pd's search path but make sure the cyclone folder is in a folder where Pd will look at, externals is a good place for this. The try to load an object like this [cyclone/avg~] and open its help file.

Have you tried the Pyo module for Python? It's a fully-featured DSP module with OSC support. http://ajaxsoundstudio.com/software/pyo/

Don't know how [http_get] works, but you can have a look at PuREST JSON library for HTTP requests.

$0 doesn't work in messages. You have to do this:

[$0 ] <- this is an object
|
[read -resize /path/to/file.aiff $1-array2( <- this is a message

the only solution I can think of is using abstractions and prepending the $0 value to your [send]/[receive] names. Example, [s $0-wireless-conn]/[r $0-wireless-conn]
There will be no conflict between different instances of abstractions as each gets a unique value associated with $0.

It's -open /path/to/patch.pd

@cfry WiringPi is deprecated due to too much pressure from its audience to its developer (actually bullying). I don't think it will be very easy to use it. You can try Python (check Sparkfun's tutorials) or even the [gpio] object (I think that's what it's called) which is by Ivica Ico Bukvic, I think.

What's the framerate of Processing? 30? Why need audio rate if your fps is 30Hz? Just use control rate OSC at that speed.

Not sure if it's relevant, but Roman Heafeli has made a non-blocking [until] abstraction. It's called [nbuntil]. Perhaps it could help with your last example.