It sounds like your main concern is there is more work than you can get done in a given day or week. Yes? If that's so, there are really only two things you ca

It sounds like your main concern is there is more work than you can get done in a given day or week. Yes? If that's so, there are really only two things you can do. Get some people who can help you, or somehow reduce the amount of work you have to do. (Or both) My advice is to talk open and honestly to the client. When you do, talk about the risks in terms of time and money. Have a list of things ready that contribute to the risk. (Some of the things you listed above) What is your business relationship with them? Freelancer, contractor, or fulltime. Are you the only person working on this? Depending on that, there might be some other things you can do.