Brian Flores Is the only Defensive HC that should be considered by the Saints. The Vikings are not going to keep him past this yr.

Dan said that he's not TOO worried , not a ringing endorsement.
Seems to me you're reading in worry into a statement that clearly shows no worry.

Also he's the rest of what he said

TCUDan: Don't get me wrong--I'm a play-calling HC and I have massive appreciation for the Andy Reids and Sean Paytons and Mike McDaniels out there.​
I don't think that is Dan saying he's "partial" to playing calling head coaches. Reads to me that he is one himself and he has a lot of appreciation for the the head coaches who are also great play callers. Appreciation for doesn't automatically mean preference for.

TCUDan: But if Rizzi has solid coordinators and a solid staff, and he leads the right way and messages, broadly emphasizes attention to detail (not being a coordinator often helps with this), he can get the job done. It's all about fostering buy-in and being a strong decision maker.​
Seems to be that TCUDan is saying that a special teams coordinator can be a good head coach and head coaches who don't call plays can have an advantage when it comes to emphasizing the attention to details.

TCUDan: His play-calling chops aren't what's going to win games late. It's gonna be his instincts and resolve when it comes to making critical decisions--and whether or not the players are bought in enough to make him right when those times come.​
Seems to mean that TCUDan is saying that head coaches have other traits that are more important to winning games, than their play calling ability.

He's partial to Play-Calling HCs.
I don't get that at all from what TCUDan said. He seems to be saying that being a good playcaller or previous OC or DC are not necessary for someone to be a good head coach. You seem to be misintepreting him having appreciation with having a prefernce for.

Rizzi is not and never has been a play-caller.
To me, TCUDan clearly said he doesn't think that's very important.

Also, Dan did not say he thought Rizzi should be the HC going forward
I never said TCUDan said Rizzi should be the HC. TCUDan didn't say that Rizzi shouldn't be the head coach either, because you didn't ask him if Rizzi should be the head coach or not.

You said that you though it was important that a head coach "has had experience coaching the offense or defense at a high level."

TCUDan seems to think that a head coach coming from an NFL special teams background is not the deal breaker that it clearly is to you.