@STP_PS:
Ohh Garonne. Thank you. You are making me blush .
I´m always up for a good debate. Stating opinions, points of view and facts along with brainstorming will hopefully get us a step ahead in order to see the truth. If there is such a thing in this world.
Now, I´ll proceed to answering the rest of your post.
I see. Maybe we have different views on how the actions unfolded. I would say " LUFFY SHOULD HAVE BEEN CAPABLE" of rendering Ceasar unconscious long before this chapter had he connected one of those powerful attacks you mentioned. However, since he didn´t use any of them he "WASN´t ABLE TO" deal with Ceasar sooner. As a comparison, think in terms of kinetic and potential energy. Potential E. becomes Kinetic E. under the appropriate circumstances.Yet, this is only one of the paths it may take as the energy could never be put to use (Luffy beating Ceasar so far) or be dissipated by outer sources and entropic stimuli. In one piece, many factors may alter the course of a fight. To show them clearer I´ll break apart Luffy´s vs CC fight in the 3 encounters they had so far.
The first time Luffy fought Ceasar, The latter won. People could argue that it was due to a Hax/cheap trick, but regardless of how it was achieved the OP story states his victory. In terms of physical strength no one would even dare to think that Ceasar is stronger than Luffy, but in terms of wits and cunningness there is a wide breadth between both headed by ceasar.
Now, the second time. Luffy was aware of the danger that Ceasar pose and found a roundabout way to avoid being stripped out of air, but he didn´t account for Monet being in the room. The harpy stepped in and saved Ceasar from defeat. Thus, Luffy wasn´t able to terminate Dr MAD Scientist CC.
The last encounter shows Luffy as someone who has dug enough into the Punk Hazard environment. As a result, Luffy understands how big of a threat and wicked CC is . Moreover he has gone beyond the "We just want to abduct CC and see what happens then" to the "I´ll send your ass off to the highest tower of this lab and beat you to a pulp- then I´ll kidnap you". As I said before, what others do influence on each character and this time it was Law´s doing (Slicing the facility) that set off CC alarm.
I guess what I´m trying to say is that in a "time room" such as that one portrayed in Kami-sama´s temple (DBZ) where you only have empty space and two contenders Luffy would have been able to deal with Ceasar faster. But in the OP world where everyone and everything counts Luffy has failed so far. Of course we presume he will finally K.O. Ceasar and kidnap him but up till chapter 691 it hasn´t happened for a number of reasons. Hence Luffy wasn´t able to stop him.
I agree with you in that Luffy is now, at least to some degree, emotionally immersed in the PH issue. Therefore, he is not fighting only for the alliance but partially for the kids and because he finds Ceasar UTTERLY DESPICABLE. I believe Ceasar killing his henchmen was the icing on the cake; it was similar to that last stroke an artist paints on his canvas. For Luffy,this was the straw that broke the camel´s back (just look at his face). What a great villain Ceasar has turned out to be.
Regarding Luffy´s attitude I hold my ground by saying that I still believe he hadn´t prolonged anything he was just unable to stop CC so far. Ceasar just turned out to be more elusive, stronger and brighter than we would think. Thus, for me, Luffy holds no fault or responsibility at all.
Finally, I´m beginning to think this might be one of those debates where depending on your standpoint, different attitudes towards the chapter´s message might arise.
so, i made a post to answer ur question twice and on both instances i wasnt able to send it :-( , so to simplify it as i really dont wanna write it again, we have different points of views. i felt after facing CC twice he should have moved with some urgency the third time and it felt like he was procrastinating. as a procrastinator when i put something off to the last minute what ever happened b/c of it is my fault. i feel luffy could have ended it with one hit and if this new move we're about to see does just that it will fortify what i thought.
i do want to say i can kinda see ur point of view but from what ive stated above and before, my deductions lead me to believe that luffy could have ended it the moment after CC explained everything.
p.s. this post sounds a bit repetitive but after two failed to send out a well thought out view point, i just cant correct it anymore lol