I did that exact thing you are talking about. You can see the result here
Is it hard? I'd say somewhat. The tough part is removing the touchscreen. The first time I tried it, I cracked it. Luckily I had another Datalux monitor and I was much more careful with that one and successfully removed the touchscreen from the housing. It's glued in so you basically have to try to apply even pressure all around the screen and gradually...GRADUALLY pry it out.
Hmmm...well you can't see much anyway. It only shows the front of it and it looks exactly as it did when it was still in the case. Honestly the only place you're going to save space by doing this is in its depth. The length and width will remain the same or very close to it. This alone though, may help you to squeeze it into the dash if there is only a small opening available. Then the fun begins trying to fasten it in there somehow.
Hmm....haven't used hibernate. I use standby though, and once out of every 25 times or so it will lose the touchscreen when it resumes. I just put it back in standby, and then resume again and it usually will come back. Not really sure how to fix this, sorry