create your entry_list.ini in the launcher. thats what i do.
I assume you mean the server's entry_list.ini. You can't run the acserverlauncher on a true dedicated server as the full game needs to be installed for it to work!
if someone doesn't have a skin and they join and get car 2 (which is the Igol skin) they are just use whatever skin they selected in single player but to everyone who has got the skin will see the Igol skin.
pretty simple really and there is no mismatch problems.
So if I launch a server only with 3rd party skins listed in the entry_list file you're saying it won't matter, I'll still be able to join in a standard car? If so what's the point of SKIN line in the entry_list file?
just open your local launcher up and create what you want, then copy the server entry_list.ini to your dedi server.
you still we be able to join, its just that you wont see the skin on the car, but others who do have the skin will see what it should be. only problem is if joe bloggs joins and everyone has the skin pack but he doesnt, all he will see is white cars.