If you are using a perspective view, then the amount the globe travels in the x and y direction is highly dependant on its depth. It will take a smaller change in x to move closer objects than it would to move farther objects the same perceived amount (i.e. a 1/4 screen). Ortho projects maintain a constant relationship, but not necessarily 1:1, so connecting mouseMoved values directly to x or y just isn't going to work.
Do you really want to move the globe? Perhaps, you just want to change the camera location/view. This is a lot easier to do with the mouse and is similar to moving the scene. Looking directly at an object and then looking to its right has the appearance of moving the object to the left. So maybe moving the view of the camera is an option for you.
As far as the texture goes, you may want to look into mipmapping your textures, esp. if you will be changing the depth (zoom in/out) and use GL_LINEAR_MIPMAP_NEAREST instead of GL_LINEAR for your GL_TEXTURE_MIN_FILTER parameter.
-Ron





