what I mean is to create the axis at arbitrary rotation compared to matlab x,y,z directions. For instance, if campos(camtarget + 50/sqrt(3)*[1,1,1]); and then create an oaxis that has for instance x' pointing toward the camera, y' toward the right of the screen and z' is up on the screen. I'm not saying it has to be define compared to the camera position, but some way to rotate it compared to original x,y,z. I agree, in general once it's define, it should remain fixed, such that it corresponds to an actual coordinate system.
1) See my answer and suggested workaround to Felix's question about multiple OAXES. It is not currently possible to have more than one OAXES exist in a given axes. I will consider it for a future release.
2) There is not a way to specify an offset. If you want to show a translated coordinate system, you could simply set the tick labels of the OAXES object to custom values representing the translated coordinates. Be sure to set the tick labels and not the ticks themselves. This trick also works on the standard MATLAB axes object - the tick labels can be independent of the values of the ticks. The drawback is that if the tick locations change (due to limit changes, etc.), the manual tick labels will be incorrect. I'll consider adding an 'offset' property in a future release.
Like many of the low-level MATLAB graphics functions, OAXES does not redraw until the MATLAB event queue is processed, which doesn't necessarily happen when you would like it to during function execution. Instead of using the PAUSE command, you can call the MATLAB function DRAWNOW() (see the help file for DRAWNOW for more information). Alternately, you can force the OAXES object to redraw by calling its DRAW() method. If you have a handle OA to the OAXES, simply call OA.draw(). If you don't have the handle, calling oaxes('draw') should also work as long as it can find the OAXES object.
I'm not sure what you mean by "rotate the axis". In 3D views, the axis lines rotate along with all other drawing objects as the camera location is moved. Trying to keep the displayed axis lines fixed on camera moves means that the lines would no longer correspond to the coordinate system. Although it would be interesting to create a camera-independent display mode for a given object (e.g. apply a transform to the object that undoes the effects of the camera location change), that is not in line with the motivation for writing OAXES.