Is the name "al-Muhsin" (the Doer of Good/Benevolent) affirmed for Allah Almighty, and accordingly, is it permissible to be named "Abd al-Muhsin" (Servant of the Doer of Good/Benevolent), based on the hadith "Indeed, Allah is Muhsin (a Doer of Good) and loves Ihsan (doing good)," which was authenticated by al-Albani and others?

The aforementioned Hadith is authentic. However, the names of Allah are Tawqifiyyah (restricted to what is revealed), and the word "Muhsin" (the Benevolent) was mentioned in the Hadith as an affirmation of Allah Almighty's benevolence, not as a name. Not every attribute can be used to name Allah. The name "Al-Muhsin" was not counted among His names in the weak Hadith narrated by At-Tirmidhi, nor in the names enumerated by Sheikh Al-Uthaymeen.