Are names such as "Wahidullah," "Ni'matullah," "Khairullah," and "Mujibullah" considered good names, or is it preferable not to name with them?

Naming someone "Wahidullah" is not advisable for two reasons: First, it may imply a sense of commendation, because "al-wahid" (the Unique) is one who has no equal. It is as if one is saying, "he has no equal in the sight of Allah." Second, it is one of the compound names that some scholars dislike using.