Ethics Vs. Marketing

While I am not sure about the first part of your question regarding how to tell if a company is actually sustainable. Regarding the questions of
Does it matter if a company’s motivation is profit, as long as the outcome is positive?
I personally do not think that it matters, having a for profit company that is doing good for the world should be the ideal that we all strive for, under a few conditions. The first condition being that their work is actually sustainable and ethical, so they don't just say it is but they actually practice it. The second condition ties into the first with the fact that hopefully their doing more than just donating to charity. Don't get me wrong, donating is a good thing but donating to charity does no good if your business is actively supporting the issues by have unethical practices.

But as long as they actually intend to do good for the world I do not see why it would be an issue, as the company would make money and they would be having a positive impact on the local community by employing people and helping them find actual decent work.