Oh wow, Ambious, you've forgotten about a lot of stuff since you watched this last, huh? Fun show for sure though, just a few things-
-The Jack the Ripper thing isn't a red herring, Jack the Ripper shows up later as a minor villain
-Dio and Jojo "become friends" because Dio starts being nice to Jojo to manipulate his dad into thinking they're all buddy buddy so Dio can do whatever he wants
-A lot of the pacing problems of the early episodes of Phantom Blood is just due to how much shorter Phantom Blood is in comparison to the other parts. It's like how SDC got two parts due to how long it was. The rest of them are due to the show trying to be as faithful to the manga as possible.
-Dio is only pretending to be drunk in order to blend in in the shitty part of town so he can stalk Jojo
-The big body small head thing is because Araki was hugely inspired by FotNS. Jonathan is basically just Kenshiro but nice.
I look forward to the future episodes! Part 1 is a slow start if you're watching the anime, but you guys got through the early part pretty quick!