A request for future updates: Doors, slabs, stairs, and a delay command

I am requesting a few things to be added in future updates or 1.9.1 if possible. These are the things on my list:

-a easier way to make doors, like maybe a new option for a block?

-slabs and stairs, so that you can have stairs and slabs to climb and make slabs stackable.

-a delay command similar to scratch.mit.edu's wait command that allows you to delay in seconds, so that you don't have any complex buggy delay functions