In your opinion do all of the failed parts of the OP's Jotul F600CB point to it being over fired?
My 600CB is 15 years old or so and is our only source of heat and ours is doing fine.
Well, our stove was over-fired before we first put it into service--that's the reason that we got it for free.
Not ever having had a wood stove before and not knowing what to look for, I replaced the obviously damaged parts (the first set of baffles and some of the gaskets) and started burning. At some point (?couple of seasons?) after reading more here--and when the new baffles started warping --I got more serious (I thought) and took the top off, replaced the burn tube assembly, the baffles and every gasket that I knew about. And there are a number of threads on the forum, where people have had to replace the burn tubes as if their failure is a routine occurrence--so I kind of thought--oh well, it's a maintenance item.
Now I think that this is not a weakness of the stove design but points to other problems with the stove's sealing.
This is where the 'you don't know what you don't know' bites you--in the posts I read about rebuilds (and even the Jotul gasket set) does not mention the ash pan cover gasket--which probably was bad from the beginning. And I do think regular replacement of this gasket is one thing that should be part of the preventative maintenance for anyone running this stove.
More than that though--if I could go back and start over, the stove should have had a total rebuild right from the beginning. Once apart, you could see where the cement had failed in the top corners (and elsewhere), and you could see where the ashpan had been leaking. I think that it was not performing properly from the first fire we lit, and it slowly degraded from there (definitely NOT helped by some rookie errors and mistakes which were probably cumulative). But there was never a time when we loaded the stove up and watched it fly past 600 degrees and just let her rip--temps (at least according to our thermo) were never that high. What we did though was burn continuously during cold spells, often for weeks at a stretch.
What I can say for sure is that it never worked as well right from when we got it as it does right now--it is truly a different stove.
I suspect at 15 years if you burn continuously, you should be thinking about a rebuild.
{Sorry for the excessively long response--the coffee had not take effect yet this morning, and I thought this was the thread about my F600]