Integrate with Libraries API & correct path (+ correct version)

Good idea. The issue you posted mentions Libraries API, which will be perfect for this. Postponed until Libraries API reaches a stable release.

Not only for libraries API, but also without it makes sense placing plugins and libraries outside the module in sites/all/libraries and sites/all/plugins. Otherwise I have no way to keep track of inside module libraries from my over 600 modules I'm maintaining on a developers install. New versions are overseen, bug fixes and security holes are overseen, libraries disappear if a new release is installed properly by removing the old module first, etc.

INSTALLATION
------------
- Place entire amfphp folder in the Drupal modules directory, or relevant site module directory
- Download AMFPHP 1.9 beta 2 from You must dowload http://downloads.sourceforge.net/amfphp/amfphp-1.9.beta.20080120.zip?mod...
- Extract AMFPHP 1.9 beta 2 modules/amfphp/amfphp inside of the amfphp module directory
- Enable the module in the admin

=>

I just extracted the 1.9 version from http://sourceforge.net/projects/amfphp/ , not the 1.9 beta2! Suppose this module should be able to work with the final release as that is supposed to be the official release; the better one and often contains bug fixes, instead of beta?

Extracted in the .../modules/amfphp library, then renaming the new folder so I get .../modules/amfphp/amfphp

Thus far so good I guess... But have a lot of additional files and folders; I don't read what to do with them, nor what files are used by this module, so I can throw the others away (some additional remnants can cause a security or performance risk for attacks to plug into them).

I have additional directories in .../modules/amfphp/
* __MACOSX
* overrides

and in .../modules/amfphp/amfphp
* browser (dir)
* core (dir)
* services (dir)
* .DS_Store
* .htaccess
* gateway.php
* globals.php
* json.php
* xmlrpc.php

I agree, sites/all/libraries is the way to go, no need to postpone this on Libraries API.