You don t have a contract, so you can t enforce payment for the third project. I would not give him website development credit or the codes for any of the sites. You have done the work, why should he be able to take credit for that or have somebody else change it, so that he can. You are not under a legal obligation to do so, as they was no written agreement or contract.I would also write-off payment for the third project and also this supposed friendship. However, I think you need qualified legal advice from somebody who is an expert in IT law to cover your questions about google ads, etc.
With this being a relatively long question, let s break it down a little.From what I can see, you have prepared and been paid for the first 2 websites. Irrespective of you charging the minimal cost, in the beginning you must have been happy to charge and accept this amount.If, he has paid for the first two websites, I would release what he needs relating to those.In relation to the 3rd website I would not make that accessible to him at all until such time it has been paid for. Deactivate it and learn from your lesson.I can understand how you feel about now having to assign these sites to him, that is to put his name on them, the only consolation being that he will not be in a position of maintaining your performance and by the sounds of it, has blown his ability to do so in the future by using your knowledge and know-how.To move forward, advise him that you want to be paid $ - (which needs to be equivalent to the cost he thought he was paying for the first two, otherwise he would not have asked you for the 3rd) in order for it to be released.In some ways, it is no different than appointing a ghostwriter to write a project, but so long as you both have a clear understanding of this from the beginning.From the sounds of it, you will be able to replicate your abilities time and time again - he will not. Learn to be more specific in your guidelines, set out a pricing quote (irrespective of who it is) and yes, move on.I hope this has helped you.Angela.PS I m a small business mentor and am often encountering operators who do not appreciate the significance of defining the terms of appointment in a simple one page document; more to make sure that both parties are clear, as opposed to legal reasons.