Yeah it sounds like you bought a former "expert" bike. They take a beating and it's common for newbies to buy from a top rider thinking the bike will be substantially better setup/maintained then they would be from the run-of-the-mill punters. Usually not the case if for no other reason than the impact loading of advanced maneuvers.
Even with good maintenance trials bikes wear and all brands have specific foibles like the case corrosion. After 8 years almost any bike that's been ridden regularly will go through a set or two of fork seals and often wheel bearings especially if pressure cleaned. The broken radiator mounts says to me that frame has seen some hard service. The exhaust pushed into the back wheel happens so frequently nobody even notices. We just grab it and bend it back. Reeds don't usually wear, they may not sit flat but that's not really a problem as they are held closed by air pressure not the spring pressure of the reed material. There's no seal on the headstock. You need to open it up now and then and keep it packed with grease. Side stand and tensioner BROKEN OFF? That should have been a good indication of some ugly work by somebody.
These are thoroughbreds and they need to be treated as such and even with extra care they will wear and they will break. The manufacturers have come out with heavier, more "reliable" models in the past and they didn't sell well so now they just give us bikes that push the envelope of performance far beyond the average rider's ability and we happily buy them.
