I have no idea, is there somewhere in the menu that logs this? I've had it about a week, so probably 50-60hrs.
Yes:
Main Menu > Help > System Info > Status 4 "C-----"
The part after the C is the operating hours.
It's too early for Dynamic, 500 hours of normal operation too early. (or 100/150h with pixel jogger)
Yeah, I tried THX but it just looks like shit.
THX should only be used for films too (preferably after the break-in, just because of mistakes like the movie ending and being left in the bluray menu for hours).
THX turns off stuff like Pixel Shifting/Pixel Orbiter and optimizes for the most stable IQ result (meaning the subfields are really refreshing the same image and not nuanced versions), combine that with full on brightness and it's the only mode that can be more harmful for the TV than Dynamic.
I'm one of those people who likes a vivid picture, not a natural one, and I've been like that my whole life (for better or worse).
I'd like to say that I'm sorry for coming across like you murdered my dog or something. But I have a vendetta against Dynamic as I'm sure you realized.
As for liking vivid colors over real colors, you're simply not used to it (having a properly calibrated set/tv) hence you are probably used to messing with TV's settings and trying to compensate on the settings for their downfalls; everybody likes colors, and it's better having them than not having them, which is really the deficit on crappy TV's.
I usually take the loudness war example to say this, but basically you probably never had top range equipment before this, hence, imagine you had some regular earbuds, you'd use them as loud as possible because they really couldn't go farther than that and their maximum still didn't feel defined enough; due to that you'd probably appreciate the fact somebody destroyed an album audio quality (*cough* RHCP's Californication *cough*) as a means to bump the sound over the walls of what was possible on your equipment. From the moment you get some good headphones everything changes, you start hearing details you were never able to before, and stuff simply sounds better. And all of a sudden stuff artificially bumped up in volume sounds like a crime, but before you realize that you'll use them the same way you always did.
Audiophiles of course, were never impressed by those shenanigans, but you'd be hard pressed for a dude that actually uses his home audio system at more than 25% sound; they sound good also because of that (not to mention being way more durable not risking blowing them). Everything "maximum" is stress, and stress is something to avoid on expensive equipment (even because sometimes they have lower thresholds because they think you know what you're doing); one good example is the THX mode on Plasmas, as it turns off some failsafe mechanisms. It assumes you know your shit.
What I mean to say is most uses and habits we create on crap equipment don't translate well (Specially out-of-the-box), because they consist in abusing something, and although something bad being abused might pose a good enough tradeoff it's rarely a good idea to do with good equipment, the good news is that, other than due to habits, you shouldn't need to.
This is my first plasma so I had no idea about the risks with doing this. There was no guidance in the manual on it, that's for sure. What's pixel jogger? I've got it sitting on the white/black slider right now and the pixel orbiter has been on the whole time since I had it.
True, I myself think Dynamic shouldn't be in these sets altogether, but you essentially fell into a stress test of a plasma during break-in.
It's not in the manual because regular use is seeing TV and films, IR is normal during the break-in and it'll go away; the current IR you have most likely will too (you didn't abuse it for that many hours) my plasma during break in (I've told you I abused it) had plenty IR, and it took hours to tone down with the Scroll Bar. After the 500 hour mark, hours of abuse just go away by changing the channel and waiting 2/3 minutes.
I could use Dynamic 100% of the time and even throw static imagery at it.
This is the pixel jogger. (complete with settings to use it, and the settings to put afterwards

)
Should I return it (store is happy to) or keep at it and hope it improves?
You have the best TV 2013 money can buy, I'd say keep it, and even if it was permanent trade it in for another while you can.
But you have a bit to learn as to how to appreciate it. (which is not much of a problem to have with a good TV set, you should enjoy it)
edit: also, why don't manufacturers just break in the panel before they ship? There's no mention of break-in in the manual or product description at all. Seems pretty anti-consumer if it's indeed a necessity.
I don't know, probably because of the fact it's a production line and they can't afford to do that, but mostly because the need for break-in is not as severe, you can actually use the TV while breaking it in now. At some point they came with breaking in DVD's and instructions to run them for hours on end.
It's a little bit like how car brands not telling you engines have a break-in period... Not even on the manual. But people in the know know that those limitations are in place, even if the engine's comes "broken-in".
That said they should certainly explain the things I just did about contrasts and the like in the manual.
Don't worry at all.
The half life the the plasma televisions are extremely high. Over the lifetime of the television it will go away.
People need to not worry about image retention / burn-in. Over the lifetime of the television it will fade out and you won't even notice it.
I know of a person that nuked an otherwise perfectly fine VT60 out of existence by using dynamic out-of-the-box complete with high brightness and hundred of hours playing the same game (Dark Souls) while he prohibited people in his place from watching TV on his "prized possession™" ie: seeing TV on this TV is a waste of operating hours, let me abuse it to no end during break-in period instead.
Fact is the use he is giving the set is something to worry about in the break-in period; he can go back to that kind of use after the panel has proper mileage in it but for the time-being he really needs to not make it any worse.