Hi there, good list of traits to consider. As a consultant myself I do 100% of my work from outsourcing that companies need. I can say as well that each company has different needs/goals when they outsource so the reason for them to outsource is often different and that needs to be considered, since every company won't have the same traits that are most important to them.

Sometimes its expertise and technical ability, sometimes though its a matter of 3rd party perspective to bring in new ideas/ creative angles, sometimes its for assessing internal work and expertise, sometimes its a matter of speed, they need something done fast and maybe with overtime or off-hours work their own team cannot do.

So, as a contractor, its important to KNOW which of these traits are most important to them and make sure to focus and deliver what they need so they are happy with your results and focus of your efforts.

Cheers mate, great post!