The biggest taboo, I don't know, but my own experience tells me - it's partners.
Don't expect a partner who holds shares and earns a salary to be as disloyal as you are. If you treat them better, they will become more responsible towards you.
He may work hard.
But he won't see and think like you do.
He will use his shareholder rights in good times. But he will not fulfill his shareholder obligations in times of adversity.
So, for partners in the early stages of entrepreneurship, it's best to have no salary if they take shares, and no shares if they receive salaries!
There is no compromise at all, there is no saying of "taking less first". Take whatever you want, no problem, wait until it's done!
If he doesn't have the money to eat, then he's not suitable for starting a business now.
If you can't do it without him, then you're not suitable for starting a business now