In re (1): We are the Free Software Foundation Europe :) It is our stance that anything that doesn't respect the user's freedoms works against the users. "[...] that usually do not work in the full interest of the user" is very, very weak language coming from us.
At the very least, it could be rephrased to "that often work against the full interest of the user", which is basically my suggestion, with "often" added.
In re (5): I can see where you're coming from. In that case, avoid mentioning "we" at all. So:
"However, this sections aims to present a small selection of apps which are fitting for starters."
Maybe also remove "however". It fits very strangely.