How long does it take for burn in to settle in?

By your own admission you have never owned a HD TV in your life. Why would you be asking this? Buy one first?

He is asking this because it may help him in his decision to buy a plasma set.

How light is the blood that stays for two hours. Does it really stay that long or will you have it paused?

I'm new to plasma sets but as far as i know you should really be concerned with bright colors that dont move after. is the blood a bright color?

I'd just be careful in the short term. Wait it out and be patient. If you read the Vizio P50 thread, you'll see some of the mentions of IR. Case in point I've owned this TV less than a month. I've been careful and watched everything stretched and lots of movies with no stationary logos. IR was quite noticable despite the brightness being lowered and contrast being lowered when I first got the set. I'm probably still shy of 100 hours (I don't watch that much TV), but it is already becoming less noticable than it was the first day I had the set. Give it some time and you'll be fine. Common sense, thats all it takes, and you won't regret the picture quality.