Click and drag is the main method. If you are simply moving the items from ship to ship, you can use the drop down menu at the bottom to first move the items to the Entrance Room (if not already there) and from there you can load them into another entity at that location that you can access. Means you can move more than just a handful of items if you have a lot you need moving.
I can agree this is easier if you only have so many items that you do not have to scroll the screen.
If you have hundreds of items that are not crated, it is a little bit harder to equip them. Not that I have had to do it too often, but holding down the mouse button with one finger and and scrolling with the other is a bit hard.
Overall this way is easier, just sucks if you have a large amount of items.
SWC is not designed to work on mobile platforms. If you can use it, great. It has been mentioned a few times to get a mobile version, but we don't have the coders to be able to do so. So, just think of it as a bonus that you can log in on a mobile platform, rather than a right.