Could all be connected to Danny's weight gain as well. I'm not one to judge, being overweight myself, but weight gain can be related to going through personal stuff and maybe it has just been a rough year for him or something. Other than Danny seeming a bit cranky (he did say he woke up just an hour before because he has a hard time sleeping on the road during the nights) the other members seemed to be having fun and they brought the positive energy. And Danny did warm up the longer the show went on and he did thank the crowd a lot after and said basically that a good crowd can really impact the gig and he thought it did.
There was some shouting for A Dying Wish and Sleepless which Danny and Vinny joked off, and Danny said "we wont play any death metal songs tonight" so they didn't seem too upset about it. I can kinda understand if Vinny would be frustrated more, because he had to fill in some shoes and do more with the keyboard, and for maybe half the show he kinda took the backseat at the back with no John available. But John being absent doesn't affect Danny much in terms of his responsibility on stage, yet maybe more on a personal level. I hope John returns though, I feel like him leaving the band would be sad not just because of what he brings musically but also him being so close with the brothers and having been in the band for so long. But hey it's just speculation. Hopefully whatever is up with his family (sickness perhaps?) will improve and he can return to the band.