Add language selector and automate multilanguage site creation

Hello, I need to create site in 2 (later maybe more) languages. I read but I propose simpler and more user friendly way.

I would welcome function that will allow me to drop a language selector on the header and then BSS would automatically copy the site 'to other language' version. When I will switch to another language version(s) I would see highlighted what I did not translate (or did not mark as 'ignore') from original site. Anything I add later into the original/primary language would be copied and 'linked to all translations' and from that point behave as stated above.

Basically text replace as all pictures would remain. Highlight function would be a plus but not crucial.

I believe something like this would be useful for many using BSS and should not be that painful from programing perspective to add into BSS.

Thanks, Juraj