1) I made the vert. stab. and then selected the polygons that would become the rudder and detached them. Now when I go into FS2004 and try to use the rudder, the entire vert. stab. rotates too.
Are BOTH parts named 'rudder'
2) I'm still a little confused about making a spinner and prop. Could anyone explain it to me! I understand that I have to make 3 copies of it but thats about it!
I suggest you read up on the aircraft modelling SDK for the correct tags (part names) and explanations. Basically xxxx_still parts display when the part should be stopped or rotating at very slow speeds; xxx_slow display at intermediate speeds; xxxx_blurred display when the part is rotating at highest speeds.
3)And finally, I created the right wing and them copied it to the left side. When I run FS the left wing is partically exposed, that is, depending on what angle I'm looking at it from, only parts of the wing are visible.
Sounds like you cloned a part and then used " mirror" from the menu or tabs... I suggest that you delete that part, then clone the right wing and apply a mirror parametric modifier