On #2, I agree with humility. But instead of taking the temperature of the room, I prefer to create the right temperature (I’m a relative control freak). I do it one of three-ish ways, either by being self-effacing to start, telling a warm story that’s easy to tell, or setting a tone of generosity and gratitude by expressing genuine thanks for being there or finding some element of the environment to celebrate.

Two other things work for me.

First, start small. Practice at Toastmasters or your local library etc in front of 10 people before you tackle full rooms. Makes it sooo much easier; makes the extra 50 people feel only marginally different from where you last were.

Second, plan for failures. Comedians do this. Come up with a smooth line if technology fails or your mind goes blank at any point. Choreograph what you would say and do. Will put both you and your audience at ease while making you less fearful of disasters.