1) when creating a webview appear indented on both edges (2-3px) and trying to enter html code by hand, they are not lost. How to be? Turns you need a stretch to fill the screen object (min-width / hieght = 100% does not help) or remove borders
2) How to remove the scroll to the right when the page is greater than the standard size (you just need to hide it)?
If you need to remove scrollbars from your _app_, read below. However, before you make any adjustments I strongly recommend testing your app on real devices. Most devices correctly hide/show and virtualize scroll bars for you, so it's not something you should have to worry about.
If you are only seeing the scroll bar in App Designer - don't worry about them. Just ignore it. App Designer wants to put scrollbars on so your content is perusable when editing.
For removing scrollbars, there are a few approaches.
Hope this helps,