3.) The font size of the headline is big enough in smaller screens which is why it displays more lines. You will have to apply responsive text if you want to display like what you wanted. You can apply the responsive text and manage it in Settings > Responsive Text
4.) You have added a negative top margin and some padding in the headline. You will need to insert an inline css in your headline element setting:
I still want the menu on mobile to scroll with the page. Now it does not. basically my problem before was that when u first started scrolling there was white space behind the menu showing.
As for the responsive text, you can edit your page in the builder then click the Cog icon (gear icon) and go to the preference section where you could add the responsive text. It’s in the screenshot provided by @RueNel.