I bet quite a few of the bmw gs1200 "adventure bikes" don't even leave the tarmac! Image is what seems to matter (shall i duck now?).
It is whatever suits you. There are pictures of an R1 upto its bobbins in clag somewhere on the forum.
If you plan on a bit of gravelly road, a road bike may be absolutely fine, good robust tyres with plenty of air in them would be useful though.
I leave a pile of spares at work for the c90, clutch, cylinder head etc, then if I needed them, would get them posted..
As has been mentioned, the bigger suzi motors have a good reputation for reliability, although 125bhp might nibble consumables. If you have a spare reg/rec, then carrying it would ensure your old one doesn't break down, but it is very easy to slip in to the trap of carrying tons of stuff you will never need! I would hazard a guess that a suzi dealer in the old eastern bloc would be able to get bits if you need them.
The most effective way of turning petrol into noise without the side-effect of horsepower