He intentionally acts like a psycho. Kotoha understand really well that his lifeline depend on those superchat money. To get those money, he must keep supplying entertaining content to his viewers. The moment he became just a boring normal person, his audience would go away, the superchat money would stop, and his supplies will quickly dries away. So treading the fine line of crazy and entertaining is a matter of life and death.
Ah... in this context, forgot the English phrase, but kind of the standard fare.
It’s like knowing market price gives you expectation about what price you’ll have to pay. In this situation, he means when facing a big enemy, the tried-and-true strategy is to go to their back or below (where they can’t reach).