First, make sure you have a good lawyer who has a lot of experience in early stage deals. Glad to recommend some for you if it's helpful. In terms of your questions:

1. If you don't know the investor well, check references, ideally with entrepreneurs they have funded. Meet the investor several times to ensure that you'd want to spend time with them in the future.

2. The angel investor can provide guidance, but as the CEO/founder, it is up to you to drive the company, figure out what needs to be done, and do it. The investor provides capital, and you runs the company.

3. Most entrepreneurs take the funding, work on their startup for a few years, and then go bankrupt. If you don't have a sense of how to make the company successful, surround yourself with experienced people and do everything in your power to figure out how to be successful, the byproduct being that you will have given your investor a nice return.