I realize it might be too late now, but thank you for your help - one of the best pieces of advice I think I've been given on here.
I have streamed defenses up to now, but that's generally because I have messed up my drafts (example: I went with the Eagles D last year. Boy, was that dumb). This year I got exactly who I wanted - the Seahawks - and it has been a pleasant surprise. It's a pleasure to be worrying about other stuff on the waiver wire, and not having to plan weeks in advance and with alternatives in case someone else nabs that great matchup you were eyeing.
The Chiefs schedule is great. Just run them until their bye in week 10, then ditch them for four weeks, missing out the Broncos completely. Hopefully they will have struggled a bit so their value will drop, and you will probably be able to pick them up for the last four weeks. I think they're a legit D, not just matchup queens.
As for using that #1 waiver wire - well yeah, it feels a bit silly to use it on the D. However, if the players you listed are the best available, then it's not exactly inspiring, and is it going to be any better in the next couple of weeks? Do you think you need to use that waiver to pickup the KC D - is someone else going to nab them?
Take what I say with a pinch of salt, because I'm lazy, and like the idea of just sitting with a D for a few weeks! I'd use the pick.