Well, after that session, I sincerely hope that my players don't figure out where I got the ideas for the hindrances that I threw in their way, thanks all.  (I don't want them coming here for ideas on getting around the things I put in their way!)

Stymied them badly by leaving the Way into the home unguarded-- then laying about three dozen slapstick-comedy physical traps between the easily-opened way into the home's dining room and the upstairs bedroom where the targets actually slept.

(To give you an idea of what I mean by "slapstick comedy" traps:  There were marbles.  Invisible marbles on a hardwood floor.  LOTS of them!  Would that I owned a digital camera, just for the looks on their faces when they realized this!)

Thanks again, all!

No problem, always happy to be of assistance. 

And there's always trickery, too. If you can trick them into inviting you in...

Ssh!  Don't help the players, please, they're sneaky enough as it is! 

EDIT: As for Changelings, they'd either lose powers like anyone else, or, like the full Fae, be bound by the traditions of hospitality (which would be a lot worse, from the perspective of doing things effectively).

Ah!  Thanks for that quoted bit-- it never occurred to me, though it certainly should have.  That nullifies that threat.

The players' idea is to kidnap a couple of warden-strength wizards from their own home in the middle of the night.  I'd like to make this a monstrous pain in the butt for them, at least.  This is helping, most certainly!

Also, like Mr. Death, I don't recall anyone Nevernever-ing their way into a threshold-guarded place.  Did I miss something?

*Edited for grammar-fiend tendencies.

Okay, we know from Changes  

So, could a powerful enough entity-- a strong wizard, for example-- with enough knowledge of the Nevernever use it to get into the living room of a romantic couple's house?  Six years together, no children, if that helps.

If so, what effect would this have on the power of the wizard?  Does this count as crossing a threshold, or has it successfully been bypassed?

Also, could you, say, let in Changelings who had not chosen yet-- and if they then chose to become Fey while in the house, would their power be reduced by being in a home uninvited?

As you can see... my players are a sneaky lot.