You make a great point: there are other potential sources of conflicts besides vendor kickbacks, and they all need to be handled with care.

It isn't always feasible, but when I'm faced with a decision where my judgment may be (or at least appear) compromised, I like to assemble the details and let my team or my management make the call. Nothing in life happens 100% without bias, but I think this helps to build trust in a similar way to your disclosing of financial ties.

The industry is quite small in a lot of ways, and reputation is everything. If people sense that you aren't trustworthy, you may still be able to find work -- but everything will get harder.

I'm glad to hear that you see value in professional trust as well and take the steps to earn it and keep it.