Constant involvement, overthinking, and their inability to distance themselves from the problem at hand makes it a real challenge to work with them successfully. With some people, it really is “my way or the highway”, which is a sad defense mechanism, when you really look at it.
In this situation, the designer has to understand that most likely all the client is doing is care. They care about their business and probably just want to help, or be useful. They see letting go of control as a potential for things to go wrong.
Sometimes they don’t express it in this way, but ultimately, that’s what it is, they want what’s best for their business.
The problem boils down to:
The bottom line is, the client needs to understand the value you bring to their business, they need to respect the terms under which you can deliver your best work, and they need to let go of their stranglehold of every minor decision that needs to be made for the product.
They need to understand they hired you for a reason, and you need to realize you have a lot of responsibility in your hands for that matter.
Act, and bill accordingly.