My answer to this question is to advise you to think completely differently. Don't think about backshifting. Don't take a sentence with one set of tenses and try to transfer it into a different set of tenses. Instead, think about the intended meaning of the sentence. What do you want to say, and what tenses will best communicate that meaning?
In other words, don't say to yourself, "This is sentence 1, how do I translate it into sentence 2?" Instead say, "How do I write sentence 2 from the start?"
And you do this by thinking about the context. Context here doesn't mean "things that are still true or yet to happen", which is what you put in one of your comments. Context means the whole story that you are telling. Context means, making it real. I'm willing to bet that you will never in your life write those sentences outside of this forum. But you will write emails to your boss and invitations for your daughter's sixteenth birthday party. You will write a blog about gardening; you will write a letter to the insurance company telling them the order of events that led to the car crash. That is context, and in each case the context will influence the tenses you use and the structure of your sentences. That is also why people who are trying to help you ask questions like "But who is Mark?" They ask, because it's part of the context and it makes a difference to the answer.
As a simple example, consider these variations:
(1) Mark said that he would make the sales presentation when she arrived. He did well, and she is now signed up.
(2) Mark said that he would make the sales presentation when she arrived. He's all ready to go, but she's not here yet and I'm getting worried.
Two stories with different contexts. The first sentence in each case is identical, and grammatically correct. But it's the second sentence in each case that answers your question about timing.
Maybe you could have a go at writing a three or four sentence narrative that includes one of your sample sentences but is more "true to life", then post it as a new question explaining the elements that you are still struggling with. I for one would be very happy to give you feedback.