No, that is not. Actually, commercial developers can be part of the community.
I really do not like your interpretation of a community as a group of amateurs or non-professionals. From my viewpoint, commercial developers can be members of the (maemo.org) community as well.
Not necessarily. A third-party commercial developer without any relationship to Nokia can exist. It can be even you, if you sell your application for money.
No, not really. Truly, we should welcome also potential commercial developers here, and be happy that they participate in maemo.org community!