webix jet in HTML page

Hi!
I have questions about the integration of webix jet and an existing site.

  1. Is it worth doing this or is it better to just take a standalone library webix?
  2. How to place elements so that they take up all the space in the window between the header and footer?
  3. Why isn’t the SVG displayed at its size?

https://snippet.webix.com/kgw98bym