See my new post for a partial response to this portion of your argument:
I’m not really seeing a dire need for this proposal. 10% effective donations has brand recognition and is a nice round number, as you point out. It is used by other groups, such as religious groups, making it easy to re-funnel donations to e.g. religious communities to effective charities. This leaves 90% of your income at your disposal, part of which you may spend on fuzzy causes. It does not seem required to me to change the 10% to allow for fuzzy donations, nor do I think there’s a motivation to make donations to fuzzy causes morally required.
See my new post for a partial response to this portion of your argument:
I appreciate the notification and will take a look!