Any chance to start WoW-client without entering a password?

[intoxx]

Why starting WoW from command line is insecure?!

Because this doesn't make any sense for 99% of people and this has been designed to be started with the official battle.net launcher (or manually with credentials) but not third party programs.

I expect that "-launcherlogin" parameter does exactly what you told in point 4 - asks for token from launcher

WoW will never ask for a token but it is being fed with it via the battle.net launcher in a way or another which is the only one supposed to handle this, nobody else is supposed to handle this, a token can provide an access to your account and that is not something they want to mess with for obvious reasons.
PS : You seem to miss-understand what's the role of the launcher here, wow.exe will never magically retrieve a token from the launcher, the launcher has to feed it. That's how it works.

Blizzard aren't going to fix it.

There is nothing to fix, that's not a bug, the login fails and that is totally normal else anybody could start an instance and login without entering any credentials.
A token is required and this is supposed to be handled by the battle.net launcher for security reasons.