1. Samsung has been fairly OK. It also can depend on your carrier. With my Galaxy S2 touch with Sprint the updates where so-so.
2. Samsung only puts Touch Wise lancher and apps on Google's OS. Which also will affect #1 above. Android has been changing alot in the last 12 months. The outlook is there will be more OS up-dates in the next 6 months.
3. I have had my GN2 for just over a week and I have never done a hard reset. Soft reset when I rooted and I like to reset every few days just to keep things clear. But I have never "needed" to reset.
Hope this helps.
Lateck,