Hello,
1) Manage alignment of the menu using menu settings of the header builder http://prntscr.com/psc0mn
2),3) What exactly is wrong with titles on the home page https://gyazo.com/f8acc3a4c7a01374c9d323bb3d1efd37 They are center-aligned according to your settings http://prntscr.com/psc8yo .
4) Disable the sidebar if you don’t need it for the cart page http://prntscr.com/psc9v5
5) Do you want to align to left the menu items? http://prntscr.com/psc51z
6) There is no option to change the font for the RTL version only.
Regards