I made an app from scratch with Ogre3D, and I'd like to integrate only collisions using bullet physics.

I understand I need to create btCollisionObject, add a shape to it (let us say a btSphereShape), and add it with btCollisionWorld::addCollisisionObject().

But how to I mirror movements of a SceneNode and a btCollisionObject ?

I also want to have not instantaneous gun bullets (eg for long range, like in max payne), and since those travel fast and are small there is a possibility of collision miss. What is the proper way of avoiding this ? Should I do a raycast at each step to check if the bullet will hit a target ?

I don't need those bullet to actually be affected by gravity or to tunnel throught multiple target, if it can save some cycles.

Continuous collision detection avoids missing collisions between fast objects, or you can chose another solution presented here.