Responsive banner bug or what?

You don't mention anything about seminarscyprus before...nevermind
but I don't see any issue regarding the menu behind the banner in there...
and regarding some menus that 'can't be clicked' that because you have a sub menus for that (parent) menu items.
the type of menu2panel you're using will ignore the menu link if they have a sub menu items (of if they as a parent menu) so if you want to have a sub menu, your parent menu should be created as a separator menu type.

That would be different case if you choose a Default layout type of menu2panel. Your parent menu will works as is whether they have sub menu items or not.

ps. i'm surprised, as an accountant you can do this all joomla things

OK I changed the default layout and now it all menu items are click-able. No problems with banner overlay as the menu opens on the left of the screen. i think I will keep this setting as it works perfectly on the iPhone as well as the desktop.

Thanks for you help, support and prompt replies (especially today). i can say MISSION ACCOMPLISHED for the menu2panel.

CASE CLOSED!

Have an outstanding day!