Investors will sort of like write the check and then, despite a lot of promises, don't usually do that much; sometimes they do.
You should be able to describe any employee as an animal at what they do.
In YC experience, 2 or 3 co-founders seems to be about perfect.
Great execution towards a terrible idea will get you nowhere.
If you don't love and believe in what you're building, you're likely to give up at some point along the way.
Here's a good rule of thumb: don't worry about a competitor at all, until they're actually beating you with a real shipped product.