RobertCo
Your brother is lucky to have a sibling who is respectful to his religious observance, regardless of your own! I commend you for offering to help out and I can assure you that both ideas are perfectly in line with general orthodox behavior.
Obviously, he and his wife may have reasons for declining which I didn’t think of, but like I said, these are generally acceptable practices.
Go ahead and offer your help – I’m sure your brother will be more than happy to discuss these offers with you!
Regardless of whether or not he accepts the offer-I’m sure he will appreciate it immensely.