Here's a summary Phil.
For things replaced, mostly just consumables, chain & sprockets, pads, etc. This bike is known to chomp fork seals off-road, and mine failed. I carried spares. Maybe neoprene boots on the forks might have helped. Likewise for wheel bearings, they are known to fail. I know another guy who has replaced them 3 times. Maybe he puts his wheel in the sand when changing tyres :-)
Stuff that broke:
The stock chain guard: is useless. Off road it bounces around until the rear mount snaps off. I had to then cut the whole guard short. I'll buy the touratech aluminum one as soon as I can.
The fan: the front wheel flicks grit up into the fan, and stops it turning. This has happened to me three times. It's easy to fix by pulling it apart and cleaning, but I have not found a permanent solution to this yet.
The rims are soft, so if you ride off-road in rocks with low pressure, you get dents in the front rim. Lots of guys change the rim for a stronger Excel rim. I didn't and it shows.
Pannier frame snapped. Welded it back up, and been fine since. Given where the bike has been, to be expected. Mines a Holan rack though, would buy it again even with this failure.
I changed the stock headlight for a HID, glad I did. It's much brighter.
I changed the footpegs for larger ones, and the shifter for a folding one. I also changed out the stock exhaust, saving a bit of weight, and making the bike narrower with panniers.
I also changed the screen for the touratech desertio. It's awesome, but stupidly expensive.
Bash plate. You've seen the stock one.... It needs something more substantial. I used an Altrider, it's been solid. Taken allot of big hits.
Other stuff added.... Barkbusters, crash bars, extra led headlights, scottoiler, MOD rear rack, headlight guard, large sidestand foot, I'd do all this stuff again.
Tyres.... Well, you already know about that! The stock ones are crap. Let me know if you need details on what I used.