Permit me to restate: Hanlon's Razor is a good thing to keep in mind to keep from becoming cynical about the whole of humanity. That said, any situation of importance (security or health, for example) has too great a risk to rely on Hanlon's Razor, and people facing these should remain vigilant.

As far as basic interpersonal relationships and other relatively low-stakes scenarios, sure, granting some benefit of the doubt can be useful when there aren't glaring red flags.

All that said, I suppose I agree with you that Hanlon's Razor is probably not broadly applicable enough in our world to be valuable as a rule of thumb. I prefer to "imagine others complexly", keeping in mind that the motivations, feelings, and histories of other people are not really reducable to simple caricatures. As such, I try not to make judgments/assumptions about why someone might say or do a particular thing, and where possible/reasonable extend them grace. This is not meant to interfere with the social contract of tolerance: anyone willfully intolerant of someone else who is protected by the contract of tolerance is not protected by the contract of tolerance.