Hi,
The category selector uses the "oTree" library.
In the HikaMarket "shop_category" type you will see this code
$status = 4;
if(!empty($next) && $next->category_parent_id == $element->category_id)
$status = 2;
It set the node state where the different states are:
* 0 - final node
* 1 - directory node closed
* 2 - directory node open
* 3 - directory node dynamic (closed)
* 4 - empty directory node
* 5 - root final node
So, if you replace the $status 2 by the value 1, you will close all directory nodes.
There is not option in the type object for such modification, I will see what is possible without breaking all the structure.
For the quantity, the best for you is to override the view in order to add some javascript which will catch the "onfocus" and "onblur" events for the quantity input.
Regards,