It's okay
You might get more responses if you start new threads for some of these questions, but I will say that changing your mind won't create insecurity or be inconsistency unless you present it as such. I usually say something like, "I see that this is more important to you than I realized. I don't like how you are talking to me. I have decided that I'm willing to give it to you. Can you ask me in a more respectful way so that I can feel better about this decision?" and then I help them be successful about asking pleasantly.