I've been testing the beta version of the web client and I have two 'complains' about both the checklists and checkboxes
After pressing the checkbox button it creates a box, after pressing enter a new checkbox is created in the next line. Then if I try to press Tab the box stays still instead of moving (this will be nice to create like a Task 1 and then Task 1.1 Task 1.2 . If press the left arrow it selects the checkbox and again the Tab key has not effect, only after pressing again the left arrow and the cursor being before the checkbox is possible to move the checkbox. You have this working quite good in the checklists, you just need to press Enter for a new checklist and Tab and it moves.
If you create the following checklist
If you try to drag the Item 2 and Item 4 for the first alignment you can do it but the Item 3 you can not do it directly, you need to move either Item 2 or 4 first