I hope you are well today and thank you for your questions.
1. i want to enlarge header (bigger length) and want to add ads banner space to it.468px x 60px
What I am wondering is if there is a way to change the width of the sidebar?
You will have to develop custom code to achieve this.
6. Is Sparkling Open Source And Free* ?
Yes it is.
2. is it legal to edit sparkling and to give it my own theme name ? OPEN Source?
Yes it’s legal as long as you provide theme credit to theme developer that is Colorlib.
4. On adding images to posts on start pages images above text and of fixed size?
5. Any way to change Header titles to Hamburger ? Menu Icon (link Mobile) on desktop and mobiles’s?
I am not sure i understood what you are trying to achieve so could you please describe it a bit more in detail?