I’ve fixed the menu item highlight issue (corrected a part of the code in your “header-functions.php” file). Thank you for bringing this up, I will also include the fix into the next theme update (1.4).
Regarding the in-page links: Kanso does have a smooth scrolling feature installed, yet at the moment it is set to only affect the menu links. If you want to include other links into this feature, you will need to alter the selector on line 576 of the “header-functions.php” file (e.g. instead of ‘.nav-smooth .main-menu a’ you can make it just ‘a’ for all links or add a specific class that you’re planning to attribute to the in-page links, e.g. ‘.nav-smooth .main-menu a, a.in-page’