The 99 hand at the beginning of the video on K73r, I like the check back on the flop but I hate the check back on the turn. If you're not betting 99 there you're really never betting anything but a good K, and that not only makes you easy to play against but makes it impossible for you to get value with what is almost definitely the best hand (and way ahead as well). It seems to me like you're taking the initial small piece of information you received (that he checked the flop instead of c-betting) and cementing your read in that alone, while ignoring other information you were given later in the hand.
Also at the beginning with the K9 hand on QJ8, I feel you need to c-bet there. You have a King and a gutshot but let's be honest, there's zero showdown value in that and getting check raised is like whatever, its just a gutshot and one overcard (and some outs are tainted by diamonds, so its a poor 'draw')... like Jay said I'd be more worried about being check raised when we have AQ there. Also, cbetting $20 into $29 only has to work like 40% of the time, so if you give the BB a reasonable flatting range (suited connectors and small pairs in addition to broadways, while capping it since he would 3bet the top of his range) you'll find that he really cant hit that flop all that often... use Flopzilla for that. With a QJ8ss board a lot of the time you could probably take him off his hand even if he check/calls because the majority of his hands that check/call are going to be pair + gutshot, like JT, 89, low diamonds, etc. His stronger hands are almost definitely check raising (and many 3betting pre as mentioned), which is actually even more of an argument for c-betting because if he just check/calls you may very well have a profitable double/triple barrel spot on some turns/rivers. Basically the point I'm trying to make is not to look at the board and say "man there's a lot of middling-high cards out there, he probably hit that hard" and instead think of his entire range and how many hands actually missed... and on top of that, keep in mind that that board hits our range too , maybe even moreso.
Also, last point, you justify checking down the 99 to the river because you think you're only going to get one street of value. The problem is that you're probably more likely to get one street of value on the turn rather than the river .... and the reason for that is because if you were bluffing with air you certainly wouldn't wait till the river to take your "stab" at the pot, and he knows that. In fact, a lot of people stab at the flop even. So when you want to value bet thinly think about what most people do with a weak hand ... the key to getting value is convincing your opponent that his hand might be better, not being certain yourself that yours is better than his. When you wait till the river your hand becomes very face up and allows him to fold things like ace-high, whereas he potentially would call with that on the turn (or some one pair hand like 78s).