1) It looks like you didn't fully understand what I wrote. If we don't bet Q4s, we have to c/c sets (or else our opponent will be happy to fold bluffcatchers). Math is done above.
2) I took 66 for my calculation because that's a pure bluffcatcher on this board. We want to make him indifferent of calling down pure bluffcatchers, I chose one. You could try others (preferably ones that don't have lots of additional equity vs our valuerange (like AK for example)).
3) That's your problem.:)
4) I answered all of your questions in the post above.
Also, it would be interesting to see you run your strategy against yourself in this spot, because you contradict yourself way too much here. Wanna call down A7 vs a range that has no K hi draws in it?
Board: Q♦J♥8♥
Equity Win Tie
MP2 87.26% 86.61% 0.65% { KK+, QhQc, QsQc, QsQh, JdJc, JsJc, JsJd, 8d8c, 8s8c, 8s8d, AhQh, AcQc, AsQs, AcJc, AdJd, AsJs, AhQc, AhQs, AcQh, AcQs, AdQh, AdQc, AdQs, AsQh, AsQc, AhJc, AhJd, AhJs, AcJd, AcJs, AdJc, AdJs, AsJc, AsJd, KhQh, KcQc, KsQs, KcJc, KdJd, KsJs, KhQc, KhQs, KcQh, KcQs, KdQh, KdQc, KdQs, KsQh, KsQc, KhJc, KhJd, KhJs, KcJd, KcJs, KdJc, KdJs, KsJc, KsJd, QcJc, QsJs, QhTh, QcTc, QsTs, Qh9h, Qc9c, Qs9s, Qc8c, Qs8s, Qh7h, Qc7c, Qs7s, Qh6h, Qc6c, Qs6s, Qh5h, Qc5c, Qs5s, Qh4h, Qc4c, Qs4s, QhJc, QhJd, QhJs, QcJd, QcJs, QsJc, QsJd, QhTc, QhTd, QhTs, QcTh, QcTd, QcTs, QsTh, QsTc, QsTd, Qh9c, Qh9d, Qh9s, Qc9h, Qc9d, Qc9s, Qs9h, Qs9c, Qs9d, Qh8c, Qh8d, Qh8s, Qc8d, Qc8s, Qs8c, Qs8d, Jc8c, Jd8d, Js8s, T9s, T7s, T9o, 97s-96s, 7h6h, 7h5h, 7h4h, 6h5h, 6h4h, 5h4h, 5h3h, 4h3h }
MP3 12.74% 12.09% 0.65% { As7s }
Good luck with that! (The same goes for betting sets but not Qx vs bluffcatching in your opponent's shoes.)
Sorry, but I can't prove it any better, and I can't find any other solution that is closer to optimal. It may be my problem, and I would be really happy if someone could prove (= mathematically point out with sound reasoning) that there's a better optimal (= meaning close to unexploitable) strategy to play this river.