Leaves too many unanswered questions (spoilers)

The movie was about Michelle, not about Howard, so it doesn't matter!

Michelle never found out what the truth was about the points you mention, so we didn't either.

The movie is about what happens to Michelle and what she does about it.

Gee Woodle, Space Kadoodle!

My personal interpretation (because I agree with the other poster that there are no concrete answers, though I think there are some strong implications):

1) I think that Howard did kill the missing girl. There's the scene where Emmett tells Michelle about not using the bus ticket to college. When she finds the ticket in his wallet later, I think that's a cue from the storytellers that Emmett was truthful. I think that Howard kidnapped Brittany to replace his daughter (who I believe was real).

2) I think it's possible that either Howard came to think of Brittany as being his daughter OR that he didn't have any pictures of himself with Meghan that were recent enough to show to Michelle.

3) The HELP was scratched on the window from the inside. I think that Brittany made it up into the place with the air filter and used her earring to scratch the message. This explains why the earring is still there and why there is blood smeared in the room. At the time that Brittany was kidnapped, there was no danger outside--she was just a girl who had been taken by a crazy dude.

4) I'm not sure if Howard intentionally drove her off the road, or if he hit her accidentally and then took her because he saw an opportunity.

5) I think that Michelle was definitely at risk. Howard displayed possessive tendencies from the first moment ("NO TOUCHING!") and was not at all hesitant to use physical intimidation in order to control Michelle.

People keep saying Howard might have been an innocent good guy. And every time I post about this movie, I have to mention the line that really seals the deal for me in terms of him being a bad guy. After he kills Emmett he says "Now it's just you and me. Just like it was always meant to be," or something like that. How in the world does that make sense if he is a good guy?

As for Michelle being "justified", I'll repeat another thing that I said in a different thread: Michelle wakes up chained to a wall. A man tells her that there has been an attack and she needs to live with him in his underground bunker for maybe two years. The man holding her captive uses physical intimidation to make her comply with what he wants. Now--when people make decisions about what to do, all they can do is use what they know and have experienced of the world. Think about how many women/girls have been kidnapped by total psychos. I could name specifically five or six just off the top of my head. Then think about how many large scale attacks (chemical or otherwise) have taken place on US soil--none. (I suppose you could say 9/11 and Pearl Harbor, but to me neither of those things require living in a bunker for 2 years). I think that any reasonable person in Michelle's shoes would act pretty much the same way that she did. You can think that maybe she was wrong, but I don't think that you can blame her one bit for the assumptions/deductions she made about what was happening to her.

My personal interpretations too :)

1) We know he lied about he name and origin, we know she was bleeding and drew a desperate help message that nobody would ever see. I suppose they were friends and he was in love, she didn't accept him so he locked he in, but she kept resisting and eventually was killed.

2) He's kinda crazy and paranoid. I think he was just lucky that some alien attack happened. If he had a dauther, he'd not need to lie about her, he'd just show a real pic. I think he wanted to talk about Brittany, he missed her, but he couldn't talk about the real thing, so he created the dauther and a fake name.

3) The help message was written months before the alien attack. Nobody would ever see it, but she was desperate and not thinking reasonably.

4) I'm not sure about that, any would be plausible. Till th time she left home, there was no sign of attack. She was hearing the boyfriend on phone and he was seeing nothing odd. Just after the call she hears radio saying that was a blackout to the south. Could it be the firs sign of the attack?

Maybe i sounded odd to Howard and he panicked, in his paranoid status. He chould have hit her, but if so and if he was in a hurry, would he stop the truck to go help her? The accident was very intense and the car went very far from the road, it took a lot of time to rescue her. I don't think he'd take all that time if he was panicked. It looks a bit more plausible to me that, when he saw someting was coming, he urged to grab some hostage to live with him. But if so, would he hit a random car without know who was inside? Or maybe he saw it was a girl and decided she was a good pray.

The other guy wasn't in the plan. I suppose that when Howard got him with her, the guy was getting there at the same time and fought his way inside. Howard had to accept it, but was sad because he wanted to live alone with the girl.

5) All we have is the info at (1). Maybe if she was docile they'd get along. Maybe he'd try to flirt on her and get mad when she didn't accept him. He's definitely paranoid and violent.

We actually do have evidence that he abducted her and that he intentionally rammed her. He said he was driving recklessly "on his way home"...except she was driving northbound, away from where he lived. If he had been telling the truth, he would have been going southbound. They were going the same direction - he came from behind and around the side. Thus, he was lying. Also, he saw her at the gas station, so he already knew what she looked like and presumably targeted her.