In Indonesia we call all Islamic preacher as Ustad and a very respectable ones will be called Ulama.
Nothing wrong with above titles.
Ustad meaning in our languages is teacher.
Alama in our language is like Phd in English.
Maula/Maulana/Sayyadi/Samad etc all are used for master. That can be The Divine or worldly master.. Some name cannot be attributed to Human like Hay-yi or Qayyum etc...
Also like Waris can be used for you offspring but in true sense Waris is only Allah as He alone owns everything..
I suppose, you didn't read the OP.
In Quran, Allah has been addressed as Mawlana, so if human being adopt such title, he is basically asking from you to call him god.