The biggest problem with the last two seasons...
I know there's a lot, but what bugs me the most is no Mystic Falls or Salvatore mansion. These characters need a home base from which to operate that represents stability as all hell is breaking loose among them. Both of these were characters on the show, and taking them away has made the show seem chaotic. Where are half of these people even living? They just seem to be helter skelter all over the place at any time, and maybe I just haven't been paying close enough attention, but I'm not even sure where half of these scenes are taking place. Are Ricks kids supposed to still be in Texas?
The show has just become random scenes with no cohesiveness to me. If you are going to have all this really bad stuff going on in their lives, there needs to also be a sense of normalcy around them as a contrast, because right now these characters just feel isolated from the outside world. For me, part of the appeal of the show was the juxtaposition of this charming, small town with all the evil goings on behind the scenes. It was like a secret world within the normal world. Now it just seems like a completely separate fantasy world. The Salvatore mansion was a reminder of the bond between the two brothers, it was a "family home," and represented all their history together. Someplace both brothers could come always come back to.
This is the last season, they need to bring it back full circle to Mystic Falls, and it will be a supreme fail if they don't IMHO.