Hi Stockplane,
Q1). Each aircraft in youre game has its own folder, if you open up the folder for the plane you want to change you will find a file with a .xdp extension. If you open the aircraft's .xdp file you will see at the top of each file a layout similar to below's example. If you want to change the name of the plane in the aircraft list in game, (that you pick your plane from in QC etc) then you need to look for the "shortname" entry in the xdp file (see blue text below) you type your new name in where I have highlighted the text in red.
<?xml version="1.0"?>
<UnitData>
<General Allegience="1" LongName="Fw 190"
ShortName="
Fw 190A-8 JG3" ModelName="ETO_fw190_A8.M3D" BlastDamageScale="1.0" ImpactDamageScale="1.0" FireDamageScale="1.0" Priority="2" Type="moving" EnteredService="11/03/1943" LeftService="12/1/1957" BlastDamageMod="1" ImpactDamageMod="1" FireDamageMod="1" Category="fighter_bomber" Country="germany" AllowSpawn="y" InfoURL="help\topics\infofw190.htm" ChecklistURL="help\topics\infofw190.htm"></General>
You now need to delete the file with the .bdp extension from the aircraft folder that you just edited the xdp file in. dont worry the game will build a new .bdp the next time you start the game.
If you get an error message whilst restarting the game about the xdp file for your plane being corrupt etc, you will have to alter your new name slightly, there are certain character types that xdp files dont like to use.
For example your new name that you suggested it may not like the II./ part rather I would type II/ instead.
Q2). For opening .dds files I suggest Martin Wrights DXTBmp program found on the site listed below.
http://www.mwgfx.co.uk/ navigate to the CFS3 section then utilities, then the DXTBmp tab, to find the download. (scroll to bottom of page for the download button)
Q3). There are many tutorials for building models in CFS3, you will need a copy of gmax to make the correctly formated model files. Its a big job but there are many people who can help out and offer advise as you learn.
regards Rob.