I'll comment (for now) only on your most frank quote regarding Kalani: "I state unapologetically that Kalani, flat out, ain't no question about it, simply does NOT have the mental make-up or capacity or horsepower to be a successful head coach. I question if he would, on his own, be a good position coach. I don't believe he would be a successful high school coach in a larger school division."
Kalani's professional resume doesn't itself disprove anything you state here. On paper, at least, he was without a doubt a risky hire — & much of his stall as well. Other than Lamb, Roderick, & Fesi — their current job positions at BYU represent a clear step up for every coach on our staff right now — that is, a clear step up from any job they'd as yet held in their careers. And yet with the exception of Mahe & Detmer, all of Kalani's initial hires at least had the professional experience to do their jobs at BYU's level of play. Kalani was also wise, I think, in hiring not only Lamb, but a contingent of his staff as well — all of whom had direct BYU connections. As Kalani said several times of his initial hires — he got guys he knew could recruit. They had a lot of ground to secure at the time since signing was barely over a month away.
I don't have enough of an insider's perspective to challenge any of your accusations against Kalani. Perhaps you do. And perhaps you have enough a handle on HCing to think Kalani's failings are at the core level & deep enough to think his flaws are beyond hope.
About the only challenge I can offer is his hires of Lamb & Grimes (& perhaps Roderick too). As long as Kalani can keep these men on staff, I do have hope that he does in fact have the horses to get our program & team on track.
Whatever his failings, Kalani does have charisma, & does have a way of bringing solid FB minds together. I think he has a solid vision of what BYU needs to do to be competitive against the upper P5. I think he has the brains, too (perhaps you have more in mind that when you say "mental makeup", I understand). I'll admit I'm not sure he has what it takes to get it done as a HC, though. I certainly haven't seen the proof yet. But his best wins do leave me hope for the time being (that & his strongest staff members, as I said).