Freddie, you've got it all correct there! Nice one.
Most of the option files will definitely include transfers as well as corrected formations and lineups.
Downloaded option files include everything that is editable in the game.
You can check out what was on the past patches for WE6:FE in the editing section:
http://forum.pesinsight.com/showthread.php?t=1366
Check out some of the links to the patches to see what they include. You can find out a lot from the pics.
Patches can include what you mentioned as well as real advertising boards (Ford, Coke, Playstation, Amstel, McDonalds etc) and new designs for balls and menus.
Since WE7 just came out, there aren't many patches available yet but when they do, you can expect the wedoit group to make some similar to the WE6:FE wedoit ones which are great (a little bit of Michelle Branch excepted...

).
You will probably need a new cable to play foreign games. The one the PS2 comes with definitely doesn't work - it shows games in black & white.
There is a great cable available at
http://www.thebarras.co.uk/shop.htm
second item down.
Jag will advise you about the Slide Card as he is "Da Sliding Man".
But the rest of your list is correct and you will be sorted to play the game soon.
Keep checking the Editing section for the latest news on patches.