Worthless,
You will also need to delete the names of the deleted aircraft from a couple of text files CFS 2 uses.
Delete them from:
mdlnames.dat
qc_plane.qcb
Don't forget to at least leave the A6M2_Zero and perhaps the P38_Lightning plane folders in place with just the "Sound" folders inside. Many add on planes alias to these planes and not having them there will cause problems with the addon planes not showing up and having to manually edit their sound.cfg files to point to something else that has a similar engine.
Whenever I start a new install, I dump all the planes from the mdlnames.dat file. I'm not sure why MS put them there, as they call up whether they are in there or not. Same with the ships. I get rid of all of those too. In fact, for the ETO, you can dump all the IJN ships from your "Ships" folder and save some more space.
I use the Mission Builder in preference to the Quick Combat feature of CFS 2. That said, I replace my Quick Combat file with one that has no planes in it and thus I avoid any conflicts within the sim.