Nivo,
It has been 8 years, but I will do my best without having the books at hand.
1. Doesn't have much, as I recall TOR around 950 Metres sea level on a 30+ degree day.
2. Around 500-550kg's with 60 US gallons per side, (ie:not full tanks, but good for 4 hours endurance). I think load more like 430kg's with full fuel, of course they do come with several different sized tanks.
NB: newer ones will come no where near this in useful load.
3. No Idea, never paid the bills.
All in all, a really usefull aeroplane, but I would probably steer clear of the pressurised versions, it's only going to cost you more in maintenance, for not much gain (if any), in performance.