As someone fairly new to morphs myself, the devil is in the details. In a killer bee or any other super pastel combo the biggest thing to look at is the head. Super pastel will blush out/severely reduce almost the entire head pattern. While similar at first glance, when you compare the head on a killer bee vs a regular bumblebee the difference becomes obvious.
As for hypo, the thing to look at is going to be the dark striations. Bumblebees alone come out with very dark stripes that tend to brown out slightly as they age, while killer bees still have the dark striations but blushed in the thicker areas. Humble bees, however, are born with noticable faded striations. Bold black markings just don't happen when hypo is present.