i dont wish to intrude or butt in but your quiery reminds me of when i started to climb first. my intro to climbing was setting up spar trees etc for skyline timber extraction. we did (very)basic climbing and aerial rescue training for that but i thought using a chainsaw aloft was maybe a bridge too far.i had about 9 years experience of forestry cutting and extraction at this stage and was often asked to fell roadside or dangerous trees.i used to climb and rig such trees and fell and pull them with a tirfor winch or with my county tractor if space permitted. if not i would leave it to the proper tree surgeons of the time (c1896-98)who were (or were percieved to be)very expensive in this part of the world. on st. stephen.s (boxing ) day 1998 there was a very violent storm and sadly a road fatality from a falling branch near here. as a result , dozens of roadside trees were condemned and lots of landowners decided to fell suspect trees. qoutations for felling these trees were (or seemed) very high. the main tree surgery company over here at the time were part of coillte (the state forestry board). all of a sudden i was being offered what seemed at the time large sums of money to fell or top trees. as a young man with a lifestyle to maintain (and an otherwise mediocre income), i was tempted into the world of tree dismantling etc. my first dismantle was a freebie for my uncle,the (spruce) tree was probably taken down in 4 inch pieces,the audience was suitably impressed and my reputation snowballed .in those days one could earn your weeks wages on a saturday domestic job (our economy was on the up also). sorry to ramble on but i think what saved me in those blissful days was good work positioning(maybe by luck ,instinct or accident)on the ground or in the tree. taking trees apart in small pieces and i suppose being already experienced (and respectful of) with chainsaws. there is really no substitute for the proper training, methods and kit. would i advise cutting /climbing without formal training? i would have to be honest and say no. im sure lots of us have had several near misses and are lucky to have come through our early careers intact. best of luck.