Better categories treeview/mutli-select

Hi
A bit disappointing are the following:
  • I have just realized that admin's categories view's select boxes can't be checked with the classic key/mouse combination: SHIFT + click (click "from" -> click "too")
  • Why not using a Jquery left-side tree-view (like any explorer) and a products list on the right (I made this for OSCommerce in 2007...it was easy)
  • Guess what you have to do if you have 1000 products displayed on your admin page, after a long click-after-click selection ? You have to scroll down to reach the bar "move/delete" ==> can't this just be css sticky !!!?
  • Please allow multi-move/remove/on-off of any kind of mix of selected categories & products.

I recommend that you make your tests with a dummy +5000 references DB and you will realize better some discomforts.
Need one ? ask me...

Regards
The category picker is a known issue.
https://github.com/litecart/litecart/issues/163

Any help is greatly appreciated.