I sharpen all my pics, otherwise they are blurry as hell, so you might want to try taht.
Very important:
Tun on your wing lights! This adds very much detail and realism to you shots.
The clouds are great, and the quality is not bad either, but you might want to try some Anitostropic Filteringandtheremycorrectspellingwent...

As for the plane, yes zoom in a bit more, for this use
F1View, with this you can go each and every direction in your VC and zoom in onto your plane.
(if you don't already have it.....)Hope my 2 cents helped

Mees
PS: Go with some sick angles! Use Recorder or if you want it easy buy W&F! Get handy with it and you'll make great shots!

Links:
IgFly's Walk and Follow:
http://www.igfly.com/F1View:
http://www.flight1software.com/files/F1View.zipRecorder:
http://www.neusinger.net/recorder/