What is the ruling on a husband refusing to leave his wife alone out of fear of falling into disobedience to Allah, and what is the ruling on his insistence on buying Islamic clothing for their newborn despite the wife preferring to buy regular clothes available in Denmark?

Islam has placed a great responsibility upon the husband towards his wife. He is commanded to oblige her to comply with the commands and prohibitions of the Shari'ah; otherwise, he would be negligent. The proof for this is Allah's saying: "O you who have believed, protect yourselves and your families from a Fire," and the Prophet's (peace be upon him) saying: "Each of you is a shepherd and is responsible for his flock. The man is a shepherd over his household and is responsible for his flock."

So, your brother's diligence concerning his wife and his fear of her deviation is a good matter for which he will be rewarded. However, it should not be a reason for his negligence in other aspects. Rather, he must balance all matters.

As for his desire to search for baby clothes free of images, it is a praiseworthy matter for which he should be thanked.