Episode 265 - So, Boo absorbing Gotenks and Piccolo carries some problems with it in terms of creativity. The most obvious one is how it essentially just makes Evil Boo a Cell knockoff without the interesting backstory or thematic tie to the main cast to make him worthwhile. The second would be how cheap his absorption is by comparison when he doesn't have to get close to his target and can just separate a piece of himself with his near limitless regeneration not having this affect him. I would say that out of the 3 main transforming DBZ villains though, it's still more interesting than Freeza's gimmick when at least Boo still requires a target to absorb rather than basically having several Uno reverse cards on hand 24/7, plus his absorption of Gotenks and Piccolo isn't inferior to Cell's absorption in every way when there's the fusion time limit to provide tension for either side in this limited time (though that will be completely erased when he absorbs Gohan).
Boo also states that he had this planned since he was fighting Gotenks. This does make it apparent he is smarter than he lets himself appear to be, though it's a shame this aspect of Boo putting up a front was never utilised later on when he started doing genuinely stupid things such as in his fight with Vegetto.
The anime adds some additional pieces to the fight such as Gohan and Boo kicking each other in the manner Goku and Jackie Chun did at the end of their fight as well as having them do Goku and Vegeta's signature poses from their first fight respectively. Some pretty nice callbacks.
Episode 266 - The anime adds Boo playing mind games with Gohan to widen the gap with him lecturing Gohan on the basics Piccolo taught him and purposely using the Makankosappo. These will of course be contradicted in the next episode where Boo has no idea who Dende is which makes it apparent he can only draw on others' techniques and not memories, though there is a decent idea here that would present how this fight could have been used to fix Gohan's characterisation. In being shown that he's not the mightiest warrior and has relied too much on his power and potential, this could have been used as a moment of growth for Gohan as he learns to improve his skill and make use of his intelligence to counter a superior foe. Instead, it amounts to a stomp match with little to make it worthwhile.
It's worth noting Elder Kaioshin is referred to here and a few prior episodes by both Kibit and Shin as Dai Kaioshin, suggesting he may have been the holder of the position in his era or that his experience grants him it by default. In any case, Rou-Dai Kaioshin sacrificing himself for Goku has a lot to provide. The most obvious is that it brings Goku back as an active member of the plot and causes some problems with the clear themes of the arc prior. I wouldn't say, however, that it damages the narrative as there's a lot to be said about the route of putting too much faith in the next generation and seeing they still have lessons to learn as well as allowing its theme to not be primarily a retread of the Cell Arc's ending. Also, as we'd see later on, it didn't necessarily become a "Goku saves the day" plot as we'd see the part about living mortals (primarily, the people of Earth united) defending Earth remained intact. The other thing to take away from Rou-Dai Kaioshin's death is him immediately getting up as a spirit, showing that Kaioshin indeed function the same when it comes to death. Considering it'd already been established that those killed by Boo such as Dabura would still go to Other World, it does make you wonder if Toriyama planned for a true, more evil version of Boo far earlier than he let on, be it Evil Boo or Pure Boo. The reveal of Vegeta's body being preserved by Enma and him being brought back to fight Boo also makes it apparent that Goku and Vegeta would work together in some way, which indeed happened.
Episode 267 - The rationale behind using Potara seems a bit unnecessary. Rou-Dai Kaioshin brings up that Boo won't just let them perform the dance, but Goku has Shunkan Ido for teleportation. It wouldn't be a difficult task for him to go to another planet or even for Kibit to Kai Kai them back to the Kaioshinkai. Of course, the reason for the Potara is the more meta one of Toriyama not wanting to retread the premise of the 12th DBZ Movie. As for its implementation as a believable part of the world, I'd say it works. It seems a stretch that the Kaioshin of Shin's generation wouldn't be taught this, but it's easy to believe it was a technique so ancient it had been forgotten by the time of Shin's generation. The flashback also shows the witch as having been on the Kaioshinkai. This may seem to clash with Kibit stating a mortal never set foot on the world before Gohan, though it could either be more ancient history the younger generation weren't aware of or that a witch of similar design to Baba had enough of a role and presence in Other World that she couldn't be counted as a mortal. In any case, that is a debate solely for the anime, as the manga's blank background makes it ambiguous where they were. With the statement that Super Saiyan drains the lifespan, I'd probably assume he was referring to the higher grades such as SS2 and SS3 as the form in general, given how Goku mastered regular Super Saiyan enough for it to be as his base self was in terms of strain.
Tenshinhan's return is good. Sure, he didn't really amount to doing much compared to his Shin Kikoho on Cell, but saving Dende is at least more shine than the other 3 main Earthling fighters were given for this arc.
Goku shows the ability to use the Kienzan to cut Boo, despite having never seen Kuririn use it. It isn't unreasonable to believe he developed the technique on his own after seeing Freeza's Death Saucer though, or that Gohan filled him in on it during the 3 year training. Vegeta did develop his own equivalent to it, after all. I don't mind the filler battle of SS3 Goku VS Gotenks Boo, considering Goku is shown at the disadvantage and Boo seems to not be taking it seriously, hence why Goku isn't oneshotted or anything. Gohan's actions here are pretty incompetent though. Apparently someone capable of reacting to punches that should be far beyond light speed lacks the co-ordination to make a simple catch? Guess Boo must have messed his eyesight up. Explains why he switches to wearing glasses after the fight.
Then there's Gohan falling into the same trap he'd seen himself and not factoring in Boo's severed antenna for this, making what should be one of the smarter characters seem so clueless.