You are using video in contact page's sidebar which means it should not exceed the width of sidebar. With couple of CSS tweaks you can fix this issue ans this class is being used in contact page sidebar >> contact-sidebar so following CSS will fix issue for you which you can add in theme-styles.css anywhere. Better add it in end of page so nothing override it, still if it does not work just include !important with the values of following CSS.
.contact-sidebar iframe,
.contact-sidebar figure {
max-width:100%;
overflow:hidden;
display:block;
}
Navigation is completely working fine for me of our demo version even in edge i don't know why you are facing that issue in edge.
You already have replaced the navigation code, so i am sorry i would not able to provide you support for this. If you have issues with our navigation in demo version or in your template without changing the navigation html or css. I can help you then else it does not relate to support i can provide you about thanks . We also don't take customization requests so better you find a CSS expert who can do these little tweaks for you it will save you time.