[Prarnenoexpog]

will it not be enough if the male mahram of the saalika gives permission to her initially to write or phone the shaikh and later she continues directly, particularly when she has to discuss something which can cause the mahram to get upset (may be about his own disobedience or mistreatment to her)?

In the end i guess it depends on the Shaykh. Some Mashaikh like Hazrat Thanvi (rah)'s view, others dont mind their Mureedas speaking to them directly.