There is a organization in Canada that utilizes the hook. Mainly to carry out flaretip changeouts and other jobs at times (although no frequent)
Regarding weights each A/C and manufacturer are quite different. Let's take a quick look at various types:
BH06 / BH47 - both have hook attached directly and only to belly. The 206 would never have the power to do any damage to airframe. The 407 is similar but the weight permitted is quite low compared to what the AC could possbily pull and you end up running in to MTOW way early.
BO105 is attached to four points on the airframe. It is acutually attached to the undercarriage if memory serves and the load is shared between each stanchion in the airframe. (The BowCow would never have enough power to damage any structure believe me)
AS332 - Here is a different system which utulized two points of hook loading. The first is that the hook may be attached directly to the airframes underbelly but has a load 60% lower then the the prefered way. The most common way is that the hook is attached to a "stripper pole". The pole is attached directly to the bottom structure of the main gearbox and down though through a hole in the floor. Similar idea as that of the 212.
Regarding longline with either of these airframes maybe my prefered AC was the 92 at times. It was a extremely stable AC to work.