Using Win32 and OpenGL in game loop? As already informed you in your previous questions, don't try to do this yourself and just use the existing implementations (JOGL or LWJGL). If you have problems with those, ask for help. Many people here have solved the problems themself and can help you too. Only a handful of people have created their own OpenGL Java wrappers and there is a reason for that: It takes a lot of time and is very hard to do well.
How to save and restore Bullet Physics state? The comment says "btSeed2 is used for re-arranging the constraint rows. improves convergence/quality of friction". Not a problem yet, but looks important later when I need to serialize constraints.