CTJ did a great job answering, but I can offer a little more…
1. Royal had two adult children die in the ‘70s. Plus, Switzer was not only cheating, not only getting away with it, but also openly taunting him, because Switzer is a true asshole.
3. I heard that Oliver Luck was the leading candidate, but in his interview, he made it clear that Mack needed to retire/be retired, and that needed to happen before he started the job. Because Luck is smart. Patterson gave assurances that he would follow Powers’ lead on the matter.
Powers needed that, because he was in a precarious political situation. Rick Perry was trying to put the same “reforms” on UT that were put on TAMU, and he was stacking the BoR with amenable people (a couple not even Exes, as it was getting more difficult to find UT grads to appoint that would do the governor’s bidding).
Mack was failing, and was using all his political connections and relationships among UT supporters in an attempt to hang on. Powers was trying to navigate Scylla (Perry) and Charybdis (Mack) and he believed he needed an AD that would do what he (Powers) told him. Powers was the key decision maker on the AD hire.
By no means do I think Powers was perfect or blameless in this, but I tend to be sympathetic to his position. I think his goals were more aligned with the university’s best interests than many of the other big players.