The DOTD remake was fantastic, perhaps even better than the original(Sorry, but I prefer my social commentaries a bit more subtle, a word not even in Romero's vocabulary).
No reason for them to go to the mall? It was close and secure, there's food and clothing and everything else needed to live in various stores for a while, and it's not like they had anywhere else to go.
The character's were stupid? Did we see the same movie? While some of them might be stereotypical they all served a purpose and were very well portrayed(Especially Michael and CJ).
Finally, the "running" aspect complaint is just a fanboy argument and holds no ground. Not even bringing in the scientific merits that they should be able to run for some time, do you not remember the VERY FIRST ZOMBIE in the original Night of the Living Dead? It was RUNNING! So can this bs argument. Snyder is a very competent director that turned a very lackluster script into a very fine film.
Miller on the other hand has no experience on a set except for Sin City- and while that no doubt helped he has very little knowledge in how to run a film. After a few more we'll see how he does, but throwing him at the sole helm of a film would not be a good idea.