Hi there, speaking of the Drum&Bass …where is the bass?
It’s over here, in the song name right after ‘&’ mark.
Seriously though, currently BeatBuddy plays drum sounds exclusively. So yes, you are correct in that ‘bass’ is missing. I think this is intentional to improve creativity - take your bass guitar and go ahead! 
Does the BB Swami predict that the aforementioned and missing bass will arrive some day, or will the name be changed to Drum & Nothing?
Certainly, I want BeatBuddy to include a complete MIDI player. But I am not the one who sets priorities and deadlines.
The Boomerang sampling pedal midi synchs to the Beat Buddy perfectly. I use a the EHX POG, and Mole and get really convincing bass with an electric. I had a Line 6 FM 4 and expression pedal for a bit and with the other listed pedals could nurse a pretty convincing dub step ‘wub wub’ out of an electric ukulele. Not really my thing but you will impress doing that live.
Since BB is IMO best as a live performance tool I strongly suggest doing your bass live. Of course what works for my workflow may not work for yours.
You might also look at the Alesis SR18 with a couple of foot switches? It is not nearly as good as BB for dynamic live performance but actually is pretty excellent if you are doing Drum and Bass live and need to use your hands mostly for other stuff.