1. I own the 125 for about a year now. Rode some 4k during that period. Thus far it hasn't given me any trouble at all. The only thing i had was the headlight suddenly stopped working. Turned out the connector vibrated of the bulb feet. Easely fixed (just squeezed it a little with a pair of pliers)
Bear in mind though, the standard tyres on it (some taiwanese brand) are really crap. They wear out fast but do not provide the grip you'd expect from a soft tyre. Especially when cornering at steep angles, the rear tends to break out. I'll be trying a couple of bridgestones next time round.
2. I really don't know what my quannon uses. Simply never cared about any of my past motorcycles about that. All i know is... its not a lot
3. I'm not sure it has a reserve
Never checked it It does however have a clear fuel indicator in the dash. Just fill her up when you've reached the last block of its display.
4. I can maintain 50 and more all day on the 125 which has slightly less power than the 150 you're looking for. Obviously when wind and steep angle roadclimbs do have a negative influence. Last weekend i took it for a trip with a friend sitting on the back and we could maintain 55 all the way. ( had to downshift at times though ).
5. Like yourself i've owned quite a number of motorcycles prior to this little gem. The last one was a honda cbr1100xx. I was amazed by the fact how 'at home' the seating position of the quannon felt. I think kymco nailed this one spot on!
6. Same here. When i migrated to spain there was no use for my over 160bhp bike anymore. The mountainroads overhere are very curvy and anything over 50bhp is just... well, overkill really. Nowadays i think its more fun to be able to constantly push the quannon to its limits rather than driving on eggs on a big bike. -I do miss the brute force though-
Good luck mate!