Boost regulator current draw seems excessive
One possibility is that you don't have an input decoupling cap, so VIN to the IC may be dropping quite a bit (in an AC sense). The resulting high VIN ripple may also be causing you to get an erroneous input voltage reading.

However, this doesn't necessarily explain why you're also seeing low efficiency in your actual application circuit - unless you are also lacking input decoupling there as well, and your input source isn't close and low impedance.

Dave