How can I start a new game without having to go through this bloody annoying "chimera hunt" tutorial sequence?

Can't. Every New Game starts with the tutorial. You can hurry and get your Arisen killed by Chimera at best.

Now, if you plan on making an industry out of New Game-ing, just do the tutorial, and after the beach assault scene the game will save.
Backup this save and every time you'll want to start over you use the copy of it - start the game in Hard Mode to get access to Character Edit(or).

Too bad. But thanks for the info.