There are links to the current editor and PulpScript documentation in the bottom right of the Pulp editor (below the theme selector).
As for controlling a multi-tile character, with the player it's easy, you just draw the extra tiles in the player's draw event handler (as shown above). Multi-tile sprites are a little tricker. We never imagined sprites would move on their own so doing that with a multi-tile sprite is an exercise left to the reader but simple behaviors are pretty easy to handle on a stationary sprite.
First, pick which tile you want to be your canonical sprite tile (I usually chose the one with the head or face). Add behavior to that one. This can be as simple as adding text in the dialogue box or more advanced behaviors with PulpScript. Then for each additional tile that make up this sprite, switch their behavior to PulpScript and implement an any event handler and call mimic, like so:
on any do
mimic "<name of the canonical sprite tile>"
end
Now when the player interacts with any of the non-canonical tiles they will behave the same as if the player had interacted with the canonical one.