If you are really concerned about the potential 3rd gear problem, Procycle in the US is now selling a replacement 3rd Gear kit for about $600US:
Suzuki DR650 Parts, Accessories, & Performance - ProCycle
I'm not sure how involved it would be changing the gears, but if my old BMW G/S is anything to go on:confused1:, you might want to have a shop do that for you. At a minimum you would want a shop manual on hand.

As to doing the NSU switch, I'd go ahead and take care of that if I were you. Despite that fact that there is a reported change in the newer bikes, I have not seen any confirmation that the screws are sufficiently secured on newer DR's. It is an easy preventative fix. A couple of notes:
1) It can be done without removing the clutch, but you might have to bend or fabricate some tools to remove/ install the screws (I welded a small bit onto an old flat head screw driver, at the right angle to get at the screws which are under the lip of the clutch basket).

2) I preemptively ordered the gasket for the clutch side, but found that my existing gasket was fine for re-use. If you have access to a local shop and the time to wait if you have to order, you might find it comes off without tearing.
3) if you can't work the screws out without removing the clutch, then maybe they are in there tight enough anyway.

I cannot explain the unusual amount of failure attributed to southern Hemisphere DR's. I find it hard to believe that it is caused by any specifically localized hard use, but I can't refute that either. There are lots of DR's in North America that are 'ridden hard and put away wet' as well. Racing? well, you got me there - I don't know of anyone racing a DR in my neck of the woods, but I'm sure it's been done.

On the DR forums I frequent it seems to be accepted as one of the engine's few, but very rare failure areas. That being said, I'd be surprised if there is a bike out there without a few issues that could end a trip. From what I know, DR's rarely fail other then from old age or poor maintenance.

Windshield - Very personal decision. I took a small universal on my first long trip, and ended up strapping it on the back for most of the days. As Mollydog said, it just made the noise/ wind blast worse, and I didn't really notice any reduced fatigue. However, for my next trip I ordered a shorter fiberglass 'dual sport fairing' that replaces the front number plate style headlight on the DR. It is sold by ADV Monster, and is designed to completely replace the DR's front headlight with two LED lights of your choice. In my case, it has provided 3 benefits:
1) a bit more wind protection, without buffeting or a shield I can't see over easily off-road. Nice and quiet, takes the wind off my chest, helmet is in 'clean' air.
2) The stock light on the DR is, well, not that great (truthfully, most bikes have lousy lights, because one 55 watt bulb isn't enough - cars get two, so we should get 110 watts right?!).
3) but, you can't just add more lights because 225 Watts is all you have (and you do want heated grips and/ or the possibility of a heated vest right?).

So by adding 2 35 watt LED lamps with an adjuster on the low beam to dial it down for safe hwy use, I save a significant 35 watts of power, and get much better lighting (or have all 60 watts on and get 'daytime' type lighting).

advmonster

I'd recommend this, but there are other screens that can work well too, so I am told. Good luck!