if you want enrich GLbasic Bethlem use C++ (better than C++?¿ faster, hardest?¿***) , for use C++ take a look to make Wrappers, the problem it's any wrapper have his own mode to done....
About bullet obviously you can make a port for GLbasic, in fact I think baccslider make a port of BulletPhysics and running but only in desktop platforms...
http://www.glbasic.com/forum/index.php?topic=7757.0 ***Excuseme but I don't know if you have C++ Skills (me not

), but here you have in the "Cristian's tongue" a hyper-fantastic explained C++ training from 0 to a mid-high level--- the guy it's a teacher from the Barcelona University... but really its' the best C++ training/trainer I find in the web , you have "C con Clase" only web very good too, but in some terms it's really complex understand the concepts...
There it's the web, with the path for do the training, you have readings, exercices and obviously the Youtube video and Channels for pick a lot of C++ code.
http://www.minidosis.org/#/