I finally confirm all that bugs.
there is no problem if you import large wave file into cubasis.
However if I import a large m4a or mp3 file into cubasis, the zooming bugs will appear.
Secondly, the audio paste hanging appears if the audio sources is from Auria audio copy.
there is no audio paste problem if the sources from Loopy...etc.
If I working with a project that importing a large m4a or mp3 files, it will easy quite apps whenever any editing.