You can ignore the css warnings - they shouldn’t have an effect.
As for the HTTP issues, widgets wind up being pretty poor solutions for company intranet portals since all the visitors typically come from one IP, exhausting the free quota pretty quickly.
A better solution would be to figure out which public feeds contain the data you want, fetch and cache them in a regular interval, and then use that cached version to render the intranet page.
The best solution would be to do all that, but use OAuth to sign the fetch, so even if your shared IP gets rate limited, you will still have full access to 350 requests/hour for the custom widget, since signed requests have quota that is shared per-user, per-app.
