At the moment when you create a bootstrap menu with a static-navbar at the top of the site, the Dnn control bar covers it so that it is very difficult to navigate when logged in as admin or host ( or vice-versa depending on the z-index you set)
A solution might be to have the control bar hidden and and activated by a tab that will display/hide the control bar. You see this allot on the skins on the Dnn store for customization.
Another idea is to have a setting ( in the site settings>appearance for example) so that you can choose where the control bar will be displayed: top, left right or bottom.
Placing this setting in the site settings will allow you to set the position per portal and not the total install.