Plot holes in Evil Dead remake?

Is it just me, or were there some major plot holes in the Evil Dead Remake? While I really enjoyed the film, there were some things that made absolutely no sense to me.

According to Wikipedia, the woman that comes out of the ground at the end is the woman we saw at the very beginning of the film. I personally thought it was A Mia clone or something until I read this.

So if it is the woman we saw at the beginning, didn't she get burned alive and take a shot gun blast to the head? How could she be back in full form?

Also Mia, scorched herself with hot water in the shower and created 3rd degree burns on herself. Although she is demonically possessed inside, her flesh would still be affected. So how in the hell did her skin return to normal after her live burial?

And, if the woman demon wasn't able to arise until five souls were claimed, then technically only four were claimed since Mia was revived from her brother.

What is the deal with Hollywood not thinking their plots through? Like in Texas Chainsaw 3D. The main girl that belonged to the crazy family was obviously in her early 20's, and it's a continuation from the events in 1974 as stated, yet everyone has the iPhone 5 and is using Face Time?

Added (1). No it didn't suck. Lol It was actually quite good. I'd give it 4/5 stars. These things just really bugged me about the film.

Knew it… The Evil Dead remake SUCKED didn't it? Good thing I didn't watch it! Army of Darkness! Woop Woop!

This evil dead is "yang" to the army of darkness. What I saw was the most anatomically real gore I have ever seen. I worked in a ER before and this was just messed up… I love? It! Do not Django this movie (judge before watching).

I give it 4 out 5 (no "guts' no glory. But they had to hold back or face an NC-17 rating).