1/. Additional aircraft get out of order in the menu with wrong pictures of the aircraft, what causes this and how do I rectify it? I have deleted and reinstalled the new aircraft from where the error started and this temporarily cured the problem, but it reappeared again later
This is probably caused by the ui_xxx= entries in the Aircraft.cfg files of the FS9 aircraft. If you refer to Aircraft.cfg of an FSX default aircraft you will see these entries are in quotes like this.
[fltsim.0]
title=Cessna Skyhawk 172SP Paint1
sim=Cessna172SP
model=
panel=
sound=
texture=1
kb_checklists=Cessna172SP_check
kb_reference=Cessna172SP_ref
atc_id=G-AAFM
ui_manufacturer=[glow=yellow,2,300]"Cessna"[/glow]
ui_type=[glow=yellow,2,300]"C172SP Skyhawk"[/glow]
ui_variation=[glow=yellow,2,300]" Blue, Gold"[/glow]
ui_typerole="Single Engine Prop"
ui_createdby="Microsoft Corporation"
description="A stable and trustworthy plane, most pilots have logged at least a few hours in a Cessna 172, since it's the most widely available aircraft in the rental fleet, and is used by most flight schools. Since the first prototype was completed in 1955, more than 35,000 C172s have been produced, making it the world's most popular single-engine plane.