Honestly, the main things you should be worried about are logos/huds/desktops. I've watched a pretty wide variety of content at this point -- window boxed, letter boxed, 4:3, etc -- and have noticed IR from differing aspect ratios goes away very quickly, even with feature length material.
OTOH, I've had slightly more stubborn IR from my windows desktop, even though I never leave it up for more than a minute or two. Even then, a couple minutes of the scrollbar wipes that away...or, I can just watch something.
In short: don't bother with wrecking the image out of worry (contrast at 50 is probably a very bad idea). Tweaking the cell light down a bit can be helpful if your are in a dark room; I'm fluctuating between 15 to 18. Basically, the lower you set it, the more stable the image will be; however, it will reduce the 'pop' of low APL, high contrast scenes.
I'm lucky in a way: I don't watch broadcast TV or sports, I don't play games much anymore, and I would never use this screen as a monitor (way too big even if it didn't burn in).
I watch at night, in blackout conditions. I use an htpc, so I don't need more hdmi ports...in fact, I already have 1 more than I need. I like a dumb TV; my computer is plenty smart enough (often, it seems smarter than me).
The one thing that does happen on this display, and, from what I've read, all samsung plasma's, is that mid to high APL scenes tend to cause blacks to rise. I've found this to be the biggest annoyance with this display. It happens the most with fullscreen (16:9) content; I've seen this in breaking bad where brighter interior shots will wash out noticeably in dark areas.
Also, you can sometimes see this black level 'pop' as the camera moves around: this is most prevalent with handheld footage; again, I've seen this on breaking bad a lot. Turning dark room optimizer off reduces this, but doesn't eliminate it. The only other things that tame it are to turn cell light down, and/or to shrink the image so it is windowboxed (not a good idea to do all the time).
Anyway, I know that last bit may sound bad, but even in worst case scenarios, this tv looks better than an LCD; and most of the time, it clobbers them. Movies tend to be less of an issue, as many are in cinemascope, have lower overall apl, and tend to have a steadier image (not as many brightness fluctuations). Just watched Wim Wenders documentary Pina last night, and while the rising blacks were noticeable in places, I never once saw any brightness fluctuation, nor did the image seem particularly dim, even in the brightest shots.