I just need to say this is probably my favorite episode this season tied with lets eat Italian food and the Koichi vs Yukako fight.
That guitar solo was beautiful. I love how shitty of a character Akira is. Red Hot Chilli Peppers is such a fun stand. I loved how he just wore some Speed Wagon uniform and tried to blame the other guy. Akira is really underappreciated by the community even though he has been the main villain for like 1/3rd of part 4.
Also on the topic of Joseph being old I sort of like it. I bet a lot of old people you look at oddly or dismiss as senile; but their history is full of adventure and overcoming adversity. Around the early 90's a lot of people's grandparents may have had a war story or two that they kept to themselves, it's hard to imagine the kind old grandparent you always had once being thrown into such difficult conflict, but they did, and then they returned to their normal lives.
Also as a bit of head cannon Joseph could have slacked on Hamon for many reasons like: there being no more vampires, or he could have wanted to age with his wife, or the trauma he went through during part 3 did a number on him, or maybe he didn't want to end up delaying the inevitable like Straights tried to do.
I believe it is interesting how Araki's plot holes leave a lot in room for head cannon.