As a boompole for lifting light loads up to high rooftops (like one square of composition shingles) Letsroll's idea would also get cautious praise in my opinion. It's the arm's length that makes it absolutely dangerous for a manlift.
In your picture of the bucket lift, there is a strap from the bucket arm to where? Top of the bucket? I think not, probably to the lift arms or crossbar so it holds the bucket to keep it from curling down or sagging due to hydraulic leakdown of the cylinders. It also looks like the overall height is not much more than a 12' stepladder. Even with this relatively safe arrangement, I think I'd want small orifices on both curl and both lift cylinders between the cylinder and the hoses so everything would move slowly in the down direction. Putting orifices on both cylinders would ensure if one cylinder failed internally or either hose failed, the other would only "slowly" bleed down. A safer arrangement for using the loader as a manlift would be pilot operated checkvalves on each cylinder just like our toplink cylinders from CCI. /forums/images/graemlins/cool.gif
Even with all those precautions, I'd want to make sure I stayed on good terms with the operator on the tractor. /forums/images/graemlins/wink.gif